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Biomedical subjects

Thomas Nickel

Publications and source records attributed to Thomas Nickel.

10 recordsLinked to original sources

[Gabapentin treatment in a female patient with panic disorder and adverse effects under carbamazepine during benzodiazepine withdrawal].

Despite their addictive potential, benzodiazepines belong to the most often prescribed drugs. We report on a patient with alprazolam dependence, who initially was treated with carbamazepine because of severe withdrawal symptoms. Due to liver enzyme elevation related to carbamazepine, we had to stop this treatment and instead of that started gabapentin treatment. Under this new therapy, the patient showed a dramatic relief of withdrawal symptoms and of the panic attacks recurring during withdrawal. Hence, due to their effectiveness and tolerability, newer anticonvulsants could be considered as medication for benzodiazepine withdrawal and as an alternative for benzodiazepine treatment in panic disorders.

Aged↗

Drugs modulating endothelial function after transplantation.

Endothelial cells play a vital role in the success or failure of a transplant procedure. The procedure itself can be viewed as a series of insults that damages the endothelium thereby triggering an inflammatory cascade that may, if uncontrolled, drive the proliferative and fibrotic processes characteristic of chronic graft vasculopathy. Unfortunately, many immunosuppressant agents contribute to this process. Glucocorticoids and the calcineurin inhibitor cyclosporine induce endothelial dysfunction, and although tacrolimus may not have the same disruptive effects on endothelial function as cyclosporine, its endothelial activity is still being established. In contrast, antiproliferative agents slow the proliferation and migration of endothelial cells and so help protect against graft vasculopathy. Researchers agree that endothelial cell dysfunction is a potentially treatable stage in the multifactorial process of graft vasculopathy and rejection. A number of cardiovascular agents (statins, angiotensin converting enzyme inhibitors, calcium channel blockers), immunoregulatory drugs, and dietary compounds have been shown to have beneficial effects on endothelial function. We briefly review the evidence supporting their use as protection for endothelial cells in transplant recipients.

Cardiovascular Agents↗

Treatment with a CRH-1-receptor antagonist (R121919) does not affect weight or plasma leptin concentration in patients with major depression.

Weight gain during treatment with psychotropic drugs is frequently observed and is assumed to be responsible for non-compliance and for an elevated risk to develop a number of somatic co-morbidities including cardiovascular disorders and type 2 diabetes. Absence of weight inducing effects is therefore a major objective for the development of new compounds. Recently, R121919, the first corticotropin releasing hormone receptor 1 (CRH1R) antagonist, was tested in major depression. Clinical efficacy, safety, and tolerability of this compound could be demonstrated. Since CRH is discussed to be involved in the regulation of appetite and weight, directly and via interaction with leptin, CRH1R antagonists are suspected to influence body weight. Effects of 30 days of treatment with the CRH1R antagonist R121919 on weight and leptin levels in 20 patients suffering from major depression were investigated. No significant weight changes during treatment with R121919 were observed. Furthermore, noeffects on plasma leptin concentrations were found. We conclude that treatment with the CRH1R antagonist R121919 does not affect weight or plasma leptin concentrations in patients with major depression. Together with previous findings indicating safety, tolerability, and clinical efficacy CRH1R antagonists are highly promising as a new treatment option in depression.

Adult↗

The combined dexamethasone/CRH test as a potential surrogate marker in depression.

There is compelling evidence that impaired corticosteroid receptor function is the key mechanism in the pathogenesis of depression resulting in a dysfunctional stress hormone regulation, which can be most sensitively detected with the combined dexamethasone (dex)/corticotropin releasing hormone (CRH) test. Treatment with different kinds of antidepressants is associated with a reduction of the hormonal responses to the combined dex/CRH test suggesting normalization of impaired corticosteroid receptor signaling as the final common pathway of these drugs. Consequently, the combined dex/CRH test is suggested as a screening tool to decide whether new compounds designed as antidepressants provide sufficient efficacy to normalize corticoid receptor signaling in depressed patients. We summarize own data and findings from the literature suggesting that (1) the neuroendocrine response to the combined dex/CRH test is elevated during a major depressive episode, but (2) tends to normalize after successful treatment. (3) Favorable response to antidepressant treatment can be predicted by determining the dex suppresser status on admission. For optimal prediction of non-response to antidepressant treatment, however, the results of a second dex/CRH test are necessary. These findings, together with the fact that impaired corticosteroid receptor signaling is considered as key mechanism of the pathogenesis in depression, support the suitability of the combined dex/CHR test as a surrogate marker for treatment response in depression. In conclusion, the combined dex/CRH test is a promising candidate to serve as a screening tool for the antidepressive effects of new compounds in clinical drug trials. Furthermore, the test appears to be capable of predicting the individual likelihood to respond to a current antidepressant treatment. If a drug treatment fails to normalize the outcome of the combined dex/CRH test, a change of the treatment strategy is recommended. Further systematic research is required and already ongoing to confirm the suitability of the combined dex/CRH test as a surrogate marker in depression.

Animals↗

Role of cytokines in cardiovascular diseases: a focus on endothelial responses to inflammation.

Complex cellular and inflammatory interactions are involved in the progress of vascular diseases. Endothelial cells, upon exposure to cytokines, undergo profound alterations of function that involve gene expression and de novo protein synthesis. The functional reprogramming of endothelial cells by cytokines is of importance especially in patients with chronic vascular inflammation. The intercellular network of dendritic cells, T-lymphocytes, macrophages and smooth muscle cells generates a variety of stimulatory cytokines [e.g. TNF-alpha (tumour necrosis factor-alpha), IL (interleukin)-1, IL-6 and IFN-gamma (interferon-gamma)] and growth factors that promote the development of functional and structural vascular changes. High concentrations of proinflammatory cytokines increase oxidative stress, down-regulate eNOS (endothelial nitric oxide synthase) bioactivity and induce endothelial cell apoptosis. Chemoattractant cytokines [e.g. VEGF (vascular endothelial growth factor), TGF-beta1 (transforming growth factor-beta1) and IL-8] are important regulators of inflammation-induced angiogenesis and are directly modulated by nitric oxide. This review will focus on the vascular mechanisms orchestrated by cytokines and summarizes the current knowledge concerning the contribution of cytokines to cardiovascular diseases.

Cardiovascular Diseases↗

Polymorphisms in FKBP5 are associated with increased recurrence of depressive episodes and rapid response to antidepressant treatment.

The stress hormone-regulating hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the causality as well as the treatment of depression. To investigate a possible association between genes regulating the HPA axis and response to antidepressants and susceptibility for depression, we genotyped single-nucleotide polymorphisms in eight of these genes in depressed individuals and matched controls. We found significant associations of response to antidepressants and the recurrence of depressive episodes with single-nucleotide polymorphisms in FKBP5, a glucocorticoid receptor-regulating cochaperone of hsp-90, in two independent samples. These single-nucleotide polymorphisms were also associated with increased intracellular FKBP5 protein expression, which triggers adaptive changes in glucocorticoid receptor and, thereby, HPA-axis regulation. Individuals carrying the associated genotypes had less HPA-axis hyperactivity during the depressive episode. We propose that the FKBP5 variant-dependent alterations in HPA-axis regulation could be related to the faster response to antidepressant drug treatment and the increased recurrence of depressive episodes observed in this subgroup of depressed individuals. These findings support a central role of genes regulating the HPA axis in the causality of depression and the mechanism of action of antidepressant drugs.

Adult↗

Clinical and neurobiological effects of tianeptine and paroxetine in major depression.

Selective serotonin reuptake inhibitors (SSRIs) are widely used as effective pharmacological agents to treat depressive disorders. In contrast to the SSRIs, which block the presynaptic serotonin (5-HT) transporter and by this route increase the concentration of serotonin in the synaptic cleft, the antidepressant tianeptine enhances the presynaptic neuronal reuptake of 5-HT and thus decreases serotonergic neurotransmission. Both SSRIs and tianeptine are clinically effective; however, their opposite modes of action challenge the prevailing concepts on the need of enhancement of serotonergic neurotransmission. To better understand the differences between these two opposite pharmacological modes of action, we compared the changes induced by tianeptine and paroxetine on psychopathology, the hypothalamic-pituitary-adrenocortical (HPA) system, and cognitive functions in a double-blind, randomized, controlled trial including 44 depressed inpatients over a period of 42 days. Depressive symptomatology significantly improved in all efficacy measures, with no significant differences between tianeptine and paroxetine. There was a trend toward better response to the SSRI among women. Assessment of the HPA system showed marked hyperactivity before the beginning of treatment, which then normalized in most of the patients, without significant differences between the two antidepressants. Cognitive assessments showed no significant differences between the two drugs investigated. The results of the current study suggest that the initial effect, i.e., enhancement or decrease of 5-HT release, is only indirectly responsible for antidepressant efficacy, and they support the notion that downstream adaptations within and between nerve cells are crucial. The normalization of the HPA system as a common mode of action of different antidepressants seems to be of special interest.

Adult↗

Treatment of depression with the CRH-1-receptor antagonist R121919: endocrine changes and side effects.

A dysregulation of the hypothalamus-pituitary-adrenocortical (HPA) system has been hypothesized to account for a myriad of cardinal symptoms of affective disorders. Specifically, increased CRH signalling via CRH type 1 receptors is thought to be an important factor in the pathogenesis of major depression and anxiety disorders. Consequently, a number of drugs have been developed in order to target the postulated increase in CRH/CRH 1 receptor signalling. One of these compounds, R121919, binds with high affinity to CRH1 receptors antagonising the action of CRH. R121919 was recently tested in an open-label study conceptualized as a safety and tolerability study. As part of this study, a thorough endocrine evaluation and detailed clinical laboratory analysis were assessed several times during 30 days of treatment with two different dose regimens of R121919 (5-40 mg vs. 40-80 mg) in 24 patients with a major depressive episode. During treatment with the experimental drug no serious side effects were noted. In particular, there were no adverse effects or impairment of the hypothalamic-pituitary-gonadal system, the hypothalamic-pituitary-thyroid axis, the renin-angiotensin system, prolactin or vasopressin secretion. Furthermore, no changes in the serum corticotropin and cortisol concentrations and in the responsivity of corticotropin and cortisol following a CRH stimulation test were noted. No effects of R121919 on clinical laboratory parameters including liver enzymes, EEG and ECG were observed. These results encourage the development of other CRH-1-R antagonists as a novel class of antidepressive drugs.

Adrenocorticotropic Hormone↗