Digital movement analysis,a new objective method of measuring tardive dyskinesia and drug-induced parkinsonian tremor: acceptability,reliability and validity

Digital movment analysis (DMA) is a new instrumental approach to assessing oral tardive dyskinesia (TD) by means of digital image processing of a video signal, tracking five paper dots placed around the patient's mouth. A total of 40 schizophrenic patients, 30 with and 10 without TD, were examined twice (with a 3-month interval) with this new device. The patients were further examined with two TD rating scales: the St. Hans Rating Scale for extrapyramidal syndromes (SHRS) and the Abnormal Involuntary Movement Scale (AIMS).The schizophrenic patients accepted the instrumental assessment without any anxiety or resistance. The internal relibility of the apparatus was high, with correlation coefficients of 0.80–0.99. The DMA TD values correlated with the SHRS and AIMS scores with correlation coefficients of 0.48–0.73 indicating an acceptable, although not strong, concurrent validity. Fluctuations occurred from the first to the second examination independent of medication. For these fluctuations no correlation was found between DMA values and rating scores. Finally, the DMA device was able to detect perioral tremor as a sign of parkinsonism.It has been concluded that DMA is a useful supplement to classical TD rating, although further validity evaluation is warranted.     

Negative symptoms in schizophrenia: considerations for clinical trials

There is little agreement about the methodology of clinical trials of antipsychotic drugs in patients with negative symptoms. A literature review revealed wide variation in experimental design, rating scales and study duration. This reflects differing views as to the definition and response to treatment of negative symptoms. Some degree of standardization would improve comparability of studies and aid the development of new compounds. Patients included in such studies should have displayed negative symptoms for at least 6 months. Depressive symptoms, positive schizophrenic symptoms and extrapyramidal signs may all influence or be confused with negative symptoms and may respond to treatment; they should be at a low level at baseline and should be measured during the study period. Studies should last at least 8 weeks. Several scales are available for measuring negative symptoms and are reviewed; a global impression score should be used additionally.     

Morphological changes in chest radiographs of patients with acute respiratory distress syndrome (ARDS)

Objective: To determine whether the quality of infiltrations in chest radiographs can accurately predict the histological extent of fibrotic change in patients with acute respiratory distress syndrome (ARDS). Design: Retrospective clinical investigation. Setting: Intensive care unit (ICU) of a university teaching hospital. Patients and methods: Of 47 patients treated with extracorporeal membrane oxygenation (ECMO) for severe ARDS over a 5-year period, 23 patients underwent open lung biopsy at thoracotomy for treatment, mostly of pneumothorax. Chest films obtained by portable chest roentgenography preceding the operation were reviewed retrospectively and compared to the histomorphological results of the lung specimen. Results: Chest radiographs displayed mixed alveolar-reticular opacification in 60.2 %, alveolar patterns in 22.9 % and reticular opacities in 10.5 %. In 0.4 % there were no infiltrates, 6 % could not be evaluated because of insufficient quality. There was no relevant difference between the right and left lungs. Subdividing patients into two groups according to the histological results of either absent or mild (1) or severe (2) lung fibrosis, we found an alveolar haziness in 12.3 % in group 1 compared with 28.2 % in group 2, while reticular characteristics were identified in 13 % and 11 %, respectively. Conclusions: The most common opacity in chest radiographs of patients with severe ARDS treated with ECMO is mixed alveolar-reticular opacification. Severe lung fibrosis is not positively correlated with a reticular radiographic pattern. ECMO does not lead to specific radiological changes in conventional radiograms, contrary to clinical findings that treatment with ECMO might induce pleural or pulmonic haemorrhage, especially in the earlier days when systemic heparinization had to be used instead of the heparin-coated tube-surfacing. Received: 24 November 1997 Accepted: 20 July 1998     

Effects of serotonergic and anticholinergic drugs in haloperidol-induced dystonia in Cebus monkeys

In rodents, serotonin (5-HT) antagonists counteract behavioral and biochemical effects of neuroleptic drugs. Therefore, we have studied the effect of different 5-HT drugs and one anticholinergic drug in acute dystonia in five cebus monkeys chronically treated with haloperidol. Acute dystonia induced by subcutaneous injections of haloperidol was slightly reduced by the 5-HT antagonist methysergide (4.0 mg/kg), while mianserin, ketanserin, and ritanserin (R 55 667; a new selective and potent 5-HT receptor blocker) had no effect. This was contrasted by the marked antidystonic effect of the anticholinergic drug biperiden (0.05-1.0 mg/kg). The 5-HT agonist citalopram, a specific 5-HT uptake inhibitor, had no significant effect. It is concluded that 5-HT antagonists have no useful effect in neuroleptic-induced dystonia.     

Inhibition of platelet aggregation following chronic in vivo treatment of rats with nicotine: prevention by simultaneous application of propranolol

Platelet aggregability is known to be enhanced and platelet-survival time shortened in smokers when compared with nonsmokers. Up to now it is unknown which of the substances in tobacco smoke are responsible for these effects. To evaluate a possible role of nicotine, rats were chronically treated with the alkaloid (10 mg/kg/day), continuously released from subcutaneously implanted osmotic minipumps. Surprisingly, after 8 weeks, platelet sensitivity toward the aggregating stimulus adenosine 5'-diphosphate (ADP) was markedly reduced. The mean ADP concentration required to induce half the maximum rate of aggregation (EC50) was 0.88 mumol/L in nicotine-treated animals, as compared with 0.67 mumol/L in controls (p less than 0.002). Platelet aggregability remained normal when the rats were treated simultaneously with nicotine and the beta blocker propranolol (3.5 mg/kg/day); for these animals, the mean EC50 for ADP was 0.73 mumol/L. These results are suggestive of a catecholamine-mediated action of nicotine. However, neither the basal levels of cAMP in platelet-rich plasma, nor the cAMP levels attained after stimulation of platelet adenylate cyclase with prostaglandin E1 (PGE1), were affected by 8 weeks of treatment with nicotine or nicotine plus propranolol. No effect on platelet aggregation was observed when the rats were treated with nicotine for only 2 weeks, or when nicotine or nicotine plus cotinine were added to platelet-rich plasma in vitro in concentrations equal to those attained in vivo after 8 weeks. Thus, prolonged application of nicotine in vivo caused an inhibition of ADP-induced rat platelet aggregation presumably mediated by beta-catecholaminergic stimulation of platelets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatocyte isolation from pig livers after warm ischaemic injury

Abstract Hepatocyte cultures have been used extensively for a wide variety of physiological, pharmacological and experimental studies. The warm ischaemic period before isolation is kept to a minimum to achieve a high yield of cells isolated and a good viability for culture. We have recently introduced a new concept of liver resuscitation after warm ischaemia that is based on a 3-h reperfusion period with an improved perfusate and simultaneous dialysis. In this study, we applied the new technique for hepatocyte isolation from livers subjected to 80 min of complete ischaemia at 37 °C. Cell yield was improved by a resuscitating perfusion from 58% to 73% and viability from 39% to 76%.