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Biomedical subjects

P Linkowski

Publications and source records attributed to P Linkowski.

At least 127 records · Page 7Linked to original sources
PubMed1979

Some neuroendocrine parameters in bipolar and unipolar depression.

There is mounting evidence showing that some pituitary and hypothalamic hormones play an important role in the affective disorders and may directly affect brain function and behavior. This report briefly reviews some recent endocrinological studies in affective illness with special reference to bipolar and unipolar form of illness. Data on prolactin and growth hormone response to levodopa in bipolar and unipolar illness presented. Preliminary data on plasma dopamine beta hydroxylase activity measured over a 24-h period are illustrated in patients suffering from bipolar and unipolar illnesses as compared to controls. The significance of these results is discussed in relation to biogenic amine dysfunction in the major affective disorders.

Adult↗
PubMed1979

Haemodialysis in schizophrenia: a double blind study - preliminary report.

The therapeutic effects of haemodialysis were evaluated in schizophrenic patients using a double blind procedure. Twelve patients were diagnosed as acute schizophrenics according to Feighner's criteria for psychopathology. After obtaining informed consent, the patients were randomly assigned to active haemodialysis (AD) or sham dialysis (SD). An 8 days "drug washout period" was followed by AD or SD treatment of 4 weeks (two 5 hours sessions per week) and psychopathological evaluations were performed regularly in a blind fashion using the Brief Psychiatry Rating Scale (BPRS) and the Comprehensive Psychopathological Rating Scale (CPRS). Nine of the 12 patients were improved by both extracorporeal procedures with or without active dialysis. No significant difference appeared however between both groups in the rate and degree of improvement of nuclear symptoms of schizophrenia. Nevertheless, AD was significantly more efficient in relieving affective symptomatology, suggesting the potential involvement of some endogenous dialysable substance (s) in the pathogenesis of mood disturbances in schizophrenia.

Adult↗
PubMed1978

Thyrotrophin, prolactin and growth hormone responses to TRH in barbiturate coma and in depression.

The effects of 200 microgram thyrotrophin-releasing hormone (TRH) i.v. on thyrotrophin (TSH), prolactin (PRL), growth hormone (GH) and triiodothyronine (T3) were studied in eight patients with barbiturate coma due to attempted suicide, in the same patients after recovery, in eight depressive patients and in eight normal controls. The patients with barbiturate coma presented normal basal TSH and PRL, elevated basal GH and normal PRL but blunted TSH responses to TRH; their GH concentrations varied widely without consistent relation to TRH administration. The same patients after recovery from coma presented normal TSH and PRL, slightly elevated basal GH, and normal PRL but blunted TSH responses to TRH; in four of these patients, a clear-cut rise in GH (i.e. more than 10 ng/ml) occurred after TRH administration. The depressive patients presented normal basal TSH and PRL, slightly elevated basal GH, and normal PRL but blunted TSH responses to TRH; in four of these patients, a moderated rise in GH (less than 10 ng/ml) occurred after TRH administration. The increment in T3 concentrations 120 min after TRH was found reduced in the comatose patients only. Basal cortisol was measured in all the subjects and found elevated in the comatose patients only. It is concluded that the abnormal TSH and GH responses to TRH observed in patients with barbiturate coma are more likely related to depressive illness than to an effect of barbiturates at the pituitary level. Barbiturates might affect thyroid secretion.

Adolescent↗
PubMed1978

Lithium accumulation in erythrocytes of manic-depressive patients: an in vivo twin study.

Genetic factors play an important role in drug metabolism and drug response. In order to investigate genetic variables in lithium prophylaxis and lithium distribution across the erythrocyte in manic-depression, we have examined forty-two pairs of twins monozygotic (n = 25) and dizygotic (n = 17) with manic-depression. Concordant twins as a group show better lithium prophylaxis than do discordant twins. These results are consistent with previously published family studies of affective illness suggesting a positive relationship between genetic background and success of lithium prophylaxis. Lithium distribution across the red blood cell (RBC) was assessed by estimating lithium RBC/plasma ratios. The lithium ratio's intrapair differences in both groups of twins were minimal with a high heritability index suggesting that genetic factors play a role in lithium ion distribution. A high linear correlation was found between lithium ratio and plasma lithium and there was no difference in lithium ratios according to sex, affective state and response to lithium. The distribution of lithium ratios was homogenous in the lithium responders' population but this was not the case in the non-responders, suggesting biological heterogeneity of lithium distribution in lithium failures. The implications of these results are discussed as they relate to the genetic determinates of lithium prophylaxis in manic-depressive illness. These results indicate that lithium ratios are of limited value in lithium maintenance therapy. Our lithium kinetic data, however, are consistent with the concept of a lithium extrusion mechanism from red blood cells.

Adult↗
PubMedDate not supplied

Life events and the dexamethasone suppression test in affective illness.

Forty patients with primary endogenous major depression were followed up during a 12-month period after recovery, on maintenance therapy. Neither the results of the DST, nor the life events reported could predict the occurrence of affective relapses although bereavement life events tended to be observed more frequently in patients relapsing, regardless of the type of antidepressant treatment.

Adult↗
PubMedDate not supplied

Seasonal variations in the dexamethasone suppression test.

One hundred and fifty-six patients from Epsom (U.K.) and Brussels, all suffering from major depressive disorder, were tested on the dexamethasone suppression test. Post-dexamethasone cortisol concentration in the plasma was found to be much lower in the winter months (November to February) than in the rest of the year.

Adult↗
PubMedDate not supplied

Sleep EEG recordings in generalized anxiety disorder with significant depression.

After one accommodation night, sleep EEG recordings were performed during three consecutive nights in ten drug-free inpatients presenting generalized anxiety disorder (GAD) with significant depression, compared with a age- and sex-matched group of patients with GAD and a group of primary major depressive disorder (MDD) patients. GAD patients with depression did not differ from GAD patients in any sleep variable. Patients with MDD showed more stage shifts and a greater number of awakenings than patients with GAD. REM latency was significantly shorter in MDD patients than in the other groups, and may thus help to differentiate anxious from depressed patients.

Adult↗
PubMedDate not supplied

The first-night effect may last more than one night.

The first-night effect in sleep polysomnographic studies is usually considered to last for one night. However, a few observations have indicated that variables associated to rapid eye movement sleep take longer to stabilize. Notwithstanding, current opinion holds that second nights of recording can be used without restriction for research and clinical purposes. The goal of this study was to describe the dynamics of habituation to polysomnography in optimal conditions. Twenty-six young, carefully screened, healthy subjects were recorded in their home for four consecutive full polysomnographies. Repeated measures ANOVA were applied. Between the two first nights, while there were no differences in sleep duration in non-rapid eye movement sleep, marked modifications in corresponding spectral power were observed. The dynamics of adaptation of rapid eye movement sleep appeared to be a process extending up to the fourth night. Similar dynamics in NREMS and REMS homeostasis have been observed in sleep deprivation studies, and it appears that the same mechanisms may be responsible for the FNE. The longer habituation process of REMS in particular has important implications for sleep research in psychiatry.

Adolescent↗
PubMedDate not supplied

[Influence of depressive history on biological parameters in major depression].

BACKGROUND: Major depressive disorder is associated with several biological abnormalities. Among them, sleep disturbances and alterations of hypothalamic structures and cortisol system have been largely studied. Most studies have found a relationship between depression and alteration of sleep. Electroencephalic sleep profiles during depression demonstrate abnormalities of sleep continuity, reduction of slow waves sleep and REM pressure (27). The cortisol system, investigated by the Dexamethasone Suppression Test (DST), is abnormal in about an half of the depressed subjects. We confirm a cortisol escape from suppression by dexamethasone (21). A complex dysregulation of the Hypothalamic Pituitary Adrenal axis (HPA) is thought to explain this escape (15, 33). The HPA has been first involved in the theory of stress. There are two ways to study this. First by looking at early adversities and genetic susceptibility to stress, and second by studying acute stressors and depressive reactions (8). The sensitization model postulated that the acute abnormalities of depression may leave biological scares. Those scares could make people more vulnerable to latter depressive triggers (34). We could then suppose that biological correlates of depression become more severe during the course of the illness. The present study further examines relationships between DST, polysomnography and some clinical and epidemiological characteristics of the depressive illness. We tried to examine if there were increasing biological disturbances during the course of the illness. We also examined the effect of the history of illness on the psychosocial stressors, and the effects of those stressors on the biological correlates of depression. METHODS: The DST and polysomnographic recordings were performed in a sample of 130 inpatients with primary major depressive disorder, unipolar form, as defined with the RDC (41). All of those patients have been consecutively admitted to the Sleep Laboratory of the Department of Psychiatry, Erasme Hospital, between 1981 and 1992. This population has been previously reported elsewhere (19, 20, 21). The depressive symptom severity was assessed with the 24-items HRSD (17). The Newcastle Endogenous Depression Diagnostic Index was used to assess the endogenous character of the depressive episode (5). The history of the illness and the impact of psychosocial stressors were assessed retrospectively using the interview associated with the RDC (41), the SADS (7). Psychosocial stressor has been assessed using the item 216 of the SADS. We must remind that it is not a precise measurement of stress. RESULTS: Table I shows clinical characteristics and biological variables in our 130 depressed patients. No correlation were found between number of depressive episodes and DST or EEG sleep records (table II). Age of onset was correlated with DST and all sleep EEG parameters (REM latency, REM density, awakening and slow wave sleep). But the age was a major confounding factor. When corrected the results for age, a significant correlation between age of onset and DST still remained, but no correlation between age of onset and EEG sleep results (table III). The psychosocial stressors were correlated only with awakening. A positive trend was found between an augmentation of psychosocial stressors and the number of episodes (p = 0.06). CONCLUSION: This study does not support the view that the biological correlates of depression are worsening with the course of the illness. We found only correlation between age of onset and DST, but a possible confounding effect of age cannot formerly be excluded. The impact of psychosocial stressors on the biological correlates of depression was minimal. The only significant correlation found was between awakening and psychosocial stressors. We found no correlation between psychosocial stressors and the course of depression. Those results do not support the view of sensitization of the illness, but it should be remember that evaluation of psychosocial stressors by item 216 of the SADS was probably not a sufficient sensitive measure. We suggest thus that the impact of the history of depression on biological correlates of depression is not very strong. An alternative explanation of the lack of correlation found is that we used inaccurate measurement of the course of depression. For example, we had no evaluation of the quality of remission between different episodes of depression and of subsyndromic depression. Recent works show the importance of this (6, 9). The major limitations of this work were the retrospective character of the study and the low precision of the evaluation of psychosocial stressors used.

Adult↗
PubMedDate not supplied

An open multicentre study to evaluate the efficacy and tolerance of fluoxetine 20 mg in depressed ambulatory patients.

In this study, 544 out-patients suffering from depressive disorders were enrolled in 6 weeks open study with fluoxetine 20 mg. A statistically significant decrease of the Hamilton Rating Scale for Depression (HRS-D) score is observed during treatment. All individual item HRS-D scores and in particular suicidal ideation, sleep disturbances and anxiety showed the same improvement. Side-effects were carefully recorded and presented a lower incidence rate than in other studies. New issues in methodology management concerning ambulatory studies are discussed.

Adult↗
PubMedDate not supplied

Naps and depression.

In healthy subjects, napping has often been seen as an "abnormal" form of sleep, while sleep has been considered as a necessary feature of life. Social and cultural biases influence the occurrence of napping behavior. However, several observations indicate the presence in man of a two per day modulation of sleep propensity. On the other hand, alterations of nocturnal sleep have been widely described in affective disorders, but little is known about the presence of daytime sleep in depressed patients and the possible effect of daytime sleep episodes on nocturnal sleep. Some attempts to characterize daytime sleep in depression are reviewed. A recent study based on continuous polygraphic recordings indicate that napping occurrence appears to be similar in depressed patients than in control subjects. However, naps structure and organization were different in depressed patients in comparison to controls. Napping seems thus to be more prevalent in depressed patients than previously assumed. Possible effects of naps on mood, alertness in depressed patients remains to be explored.

Depression↗
PubMedDate not supplied

[How does success in the 1st cycle of medical school relate to outcome in the 3rd doctorate? Behavior of 1st generation students at the Brussels Free University under the numerus clausus].

The aim of our work was to use the results of the 1st cycle of study in medical school to explore success in 3rd doctorate students in two cohorts (n = 82) of 1st generation students in the numerus clausus system. Because of the homogeneity of mean percentages in the two cohorts and the nil cohort effect on the evolution of performance across study years, the two samples were combined for further analyses. While success (end-of-year percentage) in each of the 3 years of the 1st cycle was positively correlated to success in the other two, the positions (according to ranks) of the students in their group only weakly coincided, if at all, between the 1st cycle and the 3d doctorate. The analysis of correlations between percentages in the 4 years (3 years in the 1st cycle and 3d doctorate) showed that 25% of the variance in the 3d doctorate is shared with outcome in the 1st year and only 7% with that in the 2d year; outcome in the 3d year of the 1st cycle did not contribute at all to outcome in the 3d doctorate. Besides, the chance of an excellent success in the 3d doctorate, defined as being among the 10 best performers, was positively associated to the end-of-year percentage in the 1st year, while neither 2d year nor 3d year results contributed to the prediction, as the logistic regression analysis demonstrated. These results, with a significant contribution of the 1st study year outcome to the success in the 3d doctorate of medical school, were obtained in the context of the numerus clausus and contrast with those obtained in a study preceding this selective procedure, and showing instead the 3d year of the 1st cycle as more predictive. This result could be taken as supporting the very newly established selection process at the end of the 1st study year.

Belgium↗