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Biomedical subjects

M Schou

Publications and source records attributed to M Schou.

At least 37 records · Page 2Linked to original sources

Evidence for a role of phospholipase C-gamma1 in the pathogenesis of bipolar disorder.

Several studies have indicated that patients with bipolar disorder (BD) who respond well to lithium prophylaxis constitute a biologically distinct subgroup. Lithium is thought to stabilize mood by acting at the phosphoinositide cycle. We have investigated a polymorphism located in the gene (PLCG1) that codes for a gamma-1 isozyme of phospholipase (PLC), an enzyme that plays an important role in the phosphoinositide second messenger system. A population-based association study and a family-based linkage study were carried out on patients who were considered excellent responders to lithium prophylaxis. Response to lithium was evaluated prospectively with an average follow-up of 14.4 +/- 6.8 years. The PLCG1 polymorphism was investigated in 136 excellent lithium responders and 163 controls. In addition, the segregation of this marker was studied in 32 families ascertained through lithium-responsive bipolar probands. The allele distributions between lithium-responsive bipolar patients and controls were different, with a higher frequency of one of the PLCG1 polymorphisms in patients (chi2 = 8.09; empirical P = 0.033). This polymorphism, however, confers only a small risk (OR = 1.88, CI 1.19-3.00). Linkage studies with the same marker yielded modest support for the involvement of this gene in the pathogenesis of BD when unilineal families were considered (Max LOD = 1.45; empirical P = 0.004), but not in the whole sample. Our results provide preliminary evidence that a PLC isozyme may confer susceptibility to bipolar disorder, probably accounting for a fraction of the total genetic variance. Whether this polymorphism is implicated in the pathogenesis of BD or in the mechanism of lithium response remains to be determined.

Adult↗

Has the time come to abandon prophylactic lithium treatment? A review for clinicians.

This review is based an relevant publications and addresses the following questions: Does lithium exert a recurrence-preventive, prophylactic action in manic-depressive illness? Has prophylactic treatment with anticonvulsants or antidepressants become preferable to lithium prophylaxis? Which drug or drugs should be first-choice prophylactic agent in bipolar and in unipolar manic-depressive illness?

Antidepressive Agents↗

Treating recurrent affective disorders during and after pregnancy. What can be taken safely?

Since pregnancy and the time thereafter is a precarious period for women with recurrent affective disorders and their offspring, it is important to determine the risk of various treatments for such disorders. This review assesses the risk to the fetus, the perinatal risks for mother and infant, the risks associated with treatment during the puerperium and breastfeeding, and the risks to the later development of the child. This review considers treatment with lithium, tricyclic antidepressants (TCAs), selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs), monoamine oxidase inhibitors, other antidepressants, and the anticonvulsants carbamazepine and valproic acid (sodium valproate). According to available evidence, use of lithium, TCAs and SSRIs is justified during and after pregnancy if treatment is required; no prophylactic treatment has a lower risk: benefit ratio. The review provides guidelines for the use of these drugs.

Anticonvulsants↗

Forty years of lithium treatment.

This review is based on a lecture in which I was requested to present my personal experiences and views. Since its introduction into psychiatry more than 40 years ago, lithium treatment has in most countries gained wide acceptance in the prophylaxis of unipolar and bipolar affective disorders. At one time it was feared that lithium treatment might lead to a decrease in the glomerular filtration rate, but systematically collected data indicate that even long-term treatment does not induce renal insufficiency. During treatment, regular laboratory monitoring of serum lithium and creatinine concentrations is recommended. Recent studies suggest that long-term lithium treatment does not raise the mortality of manic-depressive patients and indeed may have a mortality-lowering and antisuicidal effect. Despite the availability of alternative therapies, lithium remains the treatment of choice for the prophylaxis of recurrent manic-depressive illness.

Bipolar Disorder↗

The combat of non-compliance during prophylactic lithium treatment.

Non-compliance is the most frequent cause of recurrence during prophylactic lithium treatment and is associated with poor response and high levels of suicidality. Non-compliance is a complex phenomenon and may have a number of causes. When manic-depressive patients fare badly under the conditions of so-called 'naturalistic' trials, this usually indicates that such conditions are inadequate for long-term maintenance treatment. Prophylactic lithium treatment must be accompanied by measures to sustain compliance and counteract drop-out, and these measures build on three cornerstones, namely information, support and supervision.

Aftercare↗

Mononuclear cytotoxicity and proliferation towards glucose stimulated rodent pancreatic islet cells.

Diabetes is due to an autoimmune cellular immunologic destruction of the pancreatic beta cells. By the use of a chromium release assay and a proliferation assay we have investigated the possible role of beta cell activity for this destruction. Results show that in vitro glucose stimulated pancreatic islet cells are subjects to a slight but significantly higher cellular immunologic destruction by mononuclear spleen cells than unstimulated islet cells. The functional dependency of the islet cell destruction must be a product of both a mononuclear cell dysfunction and a specific islet cell pattern. This is due to the fact that all combinations of mononuclear cells and islet cells from diabetes prone BB rats and non-diabetes prone WF rats tested against each other, results in functional dependent cytotoxicity, except for the assay in which both effector cells and target cells are of WF rat origin. Additional observations indicate, that the diabetes prone BB rat mononuclear cells need previous in vivo activation as only cells from diabetic individuals, and not normoglycemic ones, display the reaction in question. Functional dependent cytotoxicity is validated in an other IDDM animal model--the NOD mouse. NOD mononuclear cells towards the murine MIN-6 beta cell line results in increased cellular cytotoxicity when the latter is glucose stimulated. Also the proliferative response of BB rat mononuclear cells to whole islets tend to show function dependency.

Animals↗

How to interpret findings on mortality of long-term lithium treated manic-depressive patients?! Critique of different methodological approaches.

Many studies have shown that patients with affective disorders have a mortality markedly higher than that of the general population. Studies of manic-depressive patients given prophylactic lithium treatment have yielded varying results. Some authors have reported mortalities which were more than four times that of the general population. Others have found mortalities which did not differ significantly from that of the general population. In order to examine these discrepancies we re-analysed the data of a previous study by IGSLI, using three different methods to calculate the Standardised Mortality Ratio (SMR). The data base was enlarged by adding mortality data from two additional centres. The results indicate that the discrepancies may result from the common use of a 'cumulative' approach which produces a distortion of the data if the treatment duration is not taken into consideration properly. An analysis which eliminates this artefact and takes the treatment duration into account ('year-by-year' approach) provides the strongest evidence that the mortality of lithium treated patients is not significantly different from that of the general population.

Adult↗

Mortality of patients who dropped out from regular lithium prophylaxis: a collaborative study by the International Group for the Study of Lithium-treated patients (IGSLI).

Excess mortality has repeatedly been found in patients with recurrent affective disorders. In previous studies our group has shown that during long-term lithium treatment the mortality of such patients is not significantly higher than that of the general population. In the present study, we extended our investigation to 273 patients from the earlier IGSLI cohort who subsequently dropped out from regular lithium prophylaxis. The standardized mortality ratio (SMR) for the whole group was 2.5, significantly higher (P < 0.01) than 1.0, which is the SMR of the general population. Furthermore, the SMR of the patients from each of the participating countries, namely Denmark, Germany and Austria, was significantly higher than 1.0. These findings strengthen the evidence accumulated in previous investigations that regular long-term lithium treatment does in fact markedly reduce the excess mortality of patients with recurrent affective disorders.

Antimanic Agents↗

Cytotoxicity and proliferation of splenocytes and lymph node cells from adjuvant-treated nude mice. Studies of natural and in vitro activation.

The cytotoxicity of NK cells and lymphocytes derived from nonadherent splenocytes (SPL) and regional lymph node cells (LNC) from complete Freund's adjuvant (CFA)-treated athymic nude young (4-6 weeks) and aged (over 1 year) BALB/c nu/nu mice in vitro activated with rIL-2, anti-CD3 mAb or PPD was analyzed and compared to SPL and LNC from age-matched euthymic BALB/c mice. The high natural cytotoxicity to YAC-1 target cells of SPL or LNC could be augmented by 48 h stimulation in vitro with rIL-2, especially when derived from young nude BALB/c mice. The increase in cytotoxic activity was accompanied by increased proliferative activity of both SPL and LNC, which showed statistically significant differences between the rates of stimulation of cells from the young and aged groups. Anti-CD3 mAb strongly activated the cytotoxicity of BALB/c euthymic donor effector cells against P-815 target cells, corresponding to a very high proliferative activity of these cells, but anti-CD3 mAb did not lead to activation of effector cells from nude donors. FACS analyses of antigenic markers similarly showed an increased number of T cells in LNC from aged BALB/c nude donors, which, however, never reached the levels of those of euthymic animals.

Aging↗

Excess cardiovascular and suicide mortality of affective disorders may be reduced by lithium prophylaxis.

The mortality of patients suffering from affective disorders is much higher than that of the general population; this excess is due to both suicides and cardiovascular disease. During long-term lithium treatment, the overall mortality has not been found to differ significantly from that of the general population but the question remains whether this lowering, if it is in fact caused by lithium, is due to a reduction in suicide frequency or cardiovascular mortality, or both. We analysed data from 827 previously studied patients and used a procedure that estimated both overall mortality and cause-specific mortalities by single-case analysis. For overall mortality, the ratio of observed deaths (among the patients) to expected deaths (in the general population) was 1.14, which is not significantly different from 1.0; this was also found in our previous analysis. In the whole patient group, comprising 5600 patient years under lithium treatment, seven suicides were observed and 1.3 expected, resulting in a standard mortality ratio of 5.22; this is significantly > 1.0, but markedly lower than that found in patients with affective disorders not given lithium. Cardiovascular mortality was not found to be higher in our patients than in the general population. In view of the fact that a placebo-controlled mortality study under long-term conditions is neither ethically nor practically feasible, our findings cannot prove definitively that long-term lithium treatment counteracts factors responsible for the excess suicide and cardiovascular mortality of affective disorders. However, our observations are compatible with such a notion.

Cardiovascular Diseases↗

Cytotoxicity towards neonatal versus adult BB rat pancreatic islet cells.

Cell-mediated autoimmunity is believed to influence the development of diabetes in BB rats. It has been suggested that the autoimmune destruction is due to lack of tolerance induction in early neonatal life caused by delayed maturation of the pancreatic beta cells. The present experiment has been initiated to investigate if there is any difference in in vitro cytotoxicity, and therefore antigenicity, to islet cells from neonatal, young and adult diabetes prone BB rats, and to establish the possible developmental difference in these rats compared to non diabetes prone Wistar Furth rats. Islets from rats of different ages were isolated, dispersed and 51C-labeled. In vitro cytotoxicity mediated by mononuclear spleen cells from newly diabetic BB rats was measured by counting gamma-ray emission from the culture supernatant after 16 h coincubation. We found that full adult-like islet cell maturation in BB rats--as evidenced by sensitivity to cytotoxicity--is not seen before the age of 8 to 21 days after birth. In contrast adult-like cytotoxicity to neonatal islets cells from Wistar Furth rats is seen already at the age of 8 days. Thus delayed islet cell maturation is a fact observed in BB rats.

Aging↗