Retinoic acid treatment enhances the acetylcholine contents in the human teratocarcinoma cell line NTera-2.

Human NTera-2/clone D1 teratocarcinoma cells are induced by retinoic acid (RA) to differentiate into postmitotic cells with morphological and biochemical characteristics of embryonic human neurones. Currently only limited information concerning peptide-contents and neurotransmitter pools of these cells is available. Zeller and Strauss [Int. J. Dev. Neurosci. 1995;13(5):437] described an increase in choline acetyltransferase (ChAT) activity in RA-treated, but not in untreated NTera-2 cells, suggesting the induction of a cholinergic phenotype during treatment with RA. In the present study we investigated the effect of RA-differentiation on the amount of the neurotransmitters acetylcholine (ACh), and dopamine in NTera-2 in order to specify the transmitter phenotype induced by RA-differentiation. We found that a 4-week treatment of NTera-2 cells with 10 microM RA markedly increased the ACh-content of these cells, while dopamine levels were unchanged. Depolarisation with potassium (60 mM) enhanced ACh-outflow in the differentiated cells in a Ca(++) dependent way. Also neuropeptides like substance P and NPY were detectable in the undifferentiated NTera-2 cells, while vasointestinal peptide (VIP) could not be found in either precursor or RA-differentiated cells. Differentiation was accompanied by a marked reduction of neutral endopeptidase enzyme activity and aminopeptidase activity. From these observations it was concluded that RA induces a cholinergic neurochemical differentiation of this human teratocarcinoma cell line, and that these cells might provide a model system to investigate cholinergic properties of human origin.

[Videotape preparation of patients before hip replacement surgery improves mobility after three months]. / Video-Vorbereitung bei Hüftgelenkersatz-Operation verbessert die Mobilität nach drei Monaten.

Long-term follow-up investigations of the effect of psychological preparation on postoperative physical outcome measures have very rarely been done. In this study a three-month follow-up of a previous investigation of videotape preparation before hip replacement surgery is reported. 100 patients who previously participated in a randomized controlled study received physical examination and x-ray of the hip joint three months after the operation. The mobility of the replaced hip joint was recorded as well as ossifications of the joint. Prepared patients showed a significantly higher improvement of internal rotation, rotational range of motion, and abduction, compared to the controls. The effect sizes ranged between 21% and 32% and, thus, were of clinical relevance. Prepared patients showed less ossifications (15%) that controls (22%), this difference was not significant. For the first time it could be demonstrated that psychological preparation before surgery can not only improve short-term and psychosocial outcome parameters, but also long-term physical measures. The reason for this effect remains to be investigated.

Simultaneous determination of paroxetine, risperidone and 9-hydroxyrisperidone in human plasma by high-performance liquid chromatography with coulometric detection.

A method for the simultaneous determination of paroxetine, risperidone and its main metabolite 9-hydroxyrisperidone in human plasma has been developed. The procedure involved a multistep solid-phase liquid extraction with an internal standard. The drugs were separated on a cyano column followed by coulometric detection. This method described here has sufficient sensitivity to quantitate paroxetine accurately in the range 5-500 ng/ml with a lower limit of detection of 1 ng/ml and risperidone and its main metabolite 9-hydroxyrisperidone in the range 2-100 ng/ml with a lower limit of detection of 1 ng/ml when 1 ml of plasma was used for the analysis. The precision, accuracy and specificity have been proven, and show that the method is reliable for clinical studies and routine drug monitoring.

Margatoxin and iberiotoxin, two selective potassium channel inhibitors, induce c-fos like protein and mRNA in rat organotypic dorsal striatal slices.

The isolated single organotypic slice model allows to investigate the effects of drugs and toxins on the expression of transcription factors in the striatum without dopaminergic and glutamatergic interactions. In this study the effects of margatoxin and iberiotoxin on the expression of c-fos mRNA by in situ hybridization as well as on c-fos like protein by immunohistochemistry in isolated dorsal striatum after 10 days in culture were investigated. C-fos mRNA dose-dependently increased 30 min after incubation with margatoxin and iberiotoxin. Expression of c-fos like protein was transiently detected 3h afterwards. This effect is independent from extrinsic neuronal circuitry as dopamine neurons were found to be absent in the cultured slices. It is concluded that inhibition of voltage-gated as well as calcium-activated (Slo) potassium channels leads to activation of gene transcription in striatal neurons which may trigger long-term changes in transmitter plasticity.

MDMA ('ecstasy') enhances basal acetylcholine release in brain slices of the rat striatum.

The pharmacological basis of acute (+/-)-MDMA (3, 4-methylenedioxymethamphetamine) intoxication still awaits full characterization. According to present knowledge, MDMA enhances the release of serotonin and dopamine in striatal slices and interacts with different types of receptors such as 5-HT2 (5-hydroxytryptamine or serotonin), M1 and M2 muscarinic acetylcholine (ACh), and histamine H1 receptors. Currently, no information is available about the influence of (+/-)-MDMA on striatal cholinergic neurotransmission. In the present study, we used the in vitro perfusion technique to investigate the effect of (+/-)-MDMA on ACh release in rat striatal slices. Perfusions with (+/-)-MDMA (10-300 microM) resulted in a dose-dependent increase of spontaneous ACh release (EC50 approximately 30 microM). The effect was reversible and Ca++- and tetrodotoxin-sensitive. To determine the neurochemical pathways underlying this response, we perfused with (+/-)-MDMA in the presence of various inhibitors of neurotransmitter receptors. Blockade of glutamate or muscarinic ACh receptors as well as 5-HT1, 5-HT2, 5-HT3C or dopamine D2 receptors did not modulate (+/-)-MDMA-induced ACh release. However, the presence of histamine H1 receptor antagonists in the perfusion medium abolished (+/-)-MDMA-induced ACh release. The present data clearly demonstrate that (+/-)-MDMA enhances the activity of striatal cholinergic neurons and suggest an involvement of histamine H1 receptors. The effect is not mediated by glutamate and does not involve the activation of receptors of dopamine D2, 5-HT1, 5-HT2, 5-HT3C or muscarinic ACh. Considering the relatively high affinity of (+/-)-MDMA for the H1 histamine receptor (Ki 6 microM), a direct activation of this type of receptor might represent a plausible mechanism for (+/-)-MDMA-induced ACh release.

3,4-Methylenedioxymetamphetamine (ecstasy) induces c-fos-like protein and mRNA in rat organotypic dorsal striatal slices.

3,4-Methylenedioxymetamphetamine (MDMA, "ecstasy") is an increasingly abused drug, which has significant effects on the dopamine system in the striatum. The isolated single organotypic slice model allows investigation of the effects of drugs of abuse on the expression of transcription factors in the striatum without dopaminergic and glutamatergic interactions. In this study the effects of MDMA on the expression of c-fos mRNA by in situ hybridization as well as the c-fos-like protein by immunohistochemistry in isolated dorsal striatum was investigated. It was shown that 100 microM MDMA induced c-fos mRNA expression 30 min after treatment. Expression of c-fos-like protein was transiently detected 3 h afterwards. The c-fos expression was inhibited by MK 801 and metoclopramide, indicating the involvement of dopaminergic D2 receptors and glutamatergic NMDA receptors. The dopaminergic D1 receptor antagonist SCH 23390 did not affect c-fos expression. We conclude that MDMA treatment leads to the induction of c-fos expression in isolated rat striatal slices. This effect is independent of extrinsic neuronal circuitry and seems to be associated with direct interactions between MDMA and the dopamine/glutamate receptor system.

Dopamine neurons in a simple GDNF-treated meso-striatal organotypic co-culture model.

Neurodegeneration of dopamine neurons in the ventral mesencephalon projecting to the dorsal striatum (meso-striatal system) plays a major role in Parkinson's disease. The aim of this study was to establish a simple organotypic, in vitro co-culture model for investigating the survival of dopamine neurons stimulated by the novel growth factor, glial-cell-line-derived neurotrophic factor. This model should allow investigation of the effects of the dopaminergic neurotoxin, 6-hydroxydopamine, on the expression of the transcription factor c-fos and on TUNEL staining in vitro. The dopaminotrophic factor, glial-cell-line-derived neurotrophic factor, markedly enhanced dopamine tissue levels and dopamine neuron number. Nerve-fiber ingrowth of dopamine neurons into its striatal target was found to be enhanced with glial-cell-line-derived neurotrophic factor. Using an optimized protocol, it was shown that the neurotoxin 6-hydroxydopamine selectively destructed dopamine neurons. C-fos-like immunoreactivity was enhanced in the mesencephalic part of the co-slices 3 h after application of the neurotoxin. The TUNEL staining occurred 2-5 days after the application of the neurotoxin, but did not seem to be related to dopamine neurons. In conclusion, the organotypic co-culture model provides a simple model for studying survival of dopamine neurons and for observing expression of genes and proteins that could be related to Parkinson's disease. This simple model is useful for screening novel drugs and growth factors and may markedly reduce severe animal experiments.

Videotape preparation of patients before hip replacement surgery reduces stress.

OBJECTIVE: Elective surgery represents a considerable source of stress for the patient. Many attempts have been made to prepare patients before surgery with the aim of reducing stress and improving outcome. This study used a novel approach to fulfill this aim by showing a videotape of a patient undergoing total hip replacement surgery, covering the time period from hospital admission to discharge, that strictly keeps to the patient's perspective. METHODS: Before elective total hip replacement surgery, 100 patients were randomly assigned to a control group or a preparation group; the latter group was shown the videotape on the evening before surgery. Anxiety and pain were evaluated daily for 5 days, beginning with the preoperative day, by means of the State-Trait Anxiety Inventory and a visual analog scale. Intraoperative heart rate and blood pressure, as well as postoperative intake of analgesics and sedatives, were recorded. Urinary levels of cortisol, epinephrine, and norepinephrine were determined in 12-hour samples collected at night for 5 nights, beginning with the preoperative night. RESULTS: Compared with the control group, the preparation group showed significantly less anxiety on the morning before surgery and the mornings of the first 2 postoperative days, and significantly fewer of them had an intraoperative systolic blood pressure increase of more than 15%. The pain ratings did not differ significantly between the two groups, but the prepared patients needed less analgesic medication after surgery. Prepared patients had significantly lower cortisol excretion during the preoperative night and the first 2 postoperative nights. Excretion of catecholamines did not differ significantly between groups. CONCLUSIONS: We conclude that use of the videotape decreased anxiety and stress, measured in terms of urinary cortisol excretion and intraoperative systolic blood pressure increase, in patients undergoing hip replacement surgery and prepared them to cope better with postoperative pain.