Tricyclic antidepressants. Prolonged plasma levels after overdose

Twenty-four patients hospitalized for overdose of a tricyclic antidepressant were monitored clinically, and serial plasma-drug measurements were taken for up to 144 hours. Six of 24 patients had maximum antidepressant plasma levels greater than or equal to 1,000 ng/ml, and their plasma levels at 96 hours ranged from 170 to 1,280 ng/ml. Patients ingesting substantial tricyclic overdoses may remain medically unstable for days. When high tricyclic levels persist, accurate psychiatric assessment is often impossible.     

Mitral valve malformation of Ebstein type in absence of corrected transposition

Coffee and its most important constituent, caffeine, may not only stimulate the function of many organs but also increase the metabolism in the body. These effects require a higher energy production which is mainly obtained from striated muscles by glycogenolysis and from fat tissue by lipolysis. Sutherland and Butcher were able to demonstrate that these degradation processes are primarily caused by an increase of cyclic 3,5-AMP. - In this connection caffeine and other methylxanthines are of special interest because these compounds also increase the intracellular amount of cyclic 3,5-AMP. This effect may be caused by an inhibition of phosphodiesterase, a release of catecholamines with resulting stimulation of adenylcyclase or by competitive inhibition of adenosine. At the present time it cannot be said which of these mechanisms primarily is involved in the in vivo effects of caffeine and other methylxanthines.     

Advanced renal cell carcinoma: treatment with xenogeneic immune ribonucleic acid and appropriate surgical resection

Herein we describe the first clinical treatment of renal cell carcinoma in humans with xenogeneic immune ribonucleic acid. Twelve patients with advanced renal cell carcinoma have been treated by appropriate operations to remove tumor bulk followed by specific passive immunotherapy. Xenogeneic specific immune ribonucleic acid was prepared from the spleen of normal sheep that had received 4 weekly injections of a homogenate of renal cell carcinoma. Results indicate that 1) xenogeneic specific immune ribonucleic acid can safely be given to humans without local or systemic toxicity, 2) there is a suggestion of clinical benefit, since only 2 patients have had progression of known metastases during treatment with immune ribonucleic acid and 3) xenogeneic immune ribonucleic acid can enhance the immune response to renal cell carcinoma, as demonstrated by in vitro lymphocytoxicity tests.     

Platelet density and size: the interpretation of heterogeneity

Platelets have been separated according to buoyant density using a colloidal silica-polyvinylpyrrolidone system and subjected to electronic sizing. All density populations were found to be heterogeneous in size, the most dense platelets ranging from less than 3 fl to greater than 21 fl in both man and rat. Light platelet fractions contained no platelets greater than 13 fl in either species. Cohort labeling with [75Se]selenomethionine showed no indication of significant change in platelet buoyant density with ageing; greater specific activity found in young, dense platelets appears to be related to increased protein synthetic activity shown in vitro and likely to occur also in their precursor megakaryocytes. It is postulated that dense, intermediate and light platelets are released synchronously by the three different ploidy classes of megakaryocyte, that varying density indicates differing structural characteristics and presumably differences in function. The present findings do not deny the possibility that platelets decrease in size with ageing but if such occurs, it is not associated with a significant change in platelet buoyant density.     

Response of stem cells in the mouse testis to fission neutrons of 1 MeV mean energy and 300 kV x rays. Methodology, dose-response studies, relative biological effectiveness

Microelectrode recording in the thalamus of pigeons subjected to tilt and sinusoidal rotational stimuli around the vertical, longitudinal and transversal axes revealed vestibularly driven units in two thalamic nuclei, the nucleus posteroventralis and the nucleus principalis precommissuralis. Many of these units responded in a complex manner suggesting that inputs from contralateral and ipsilateral cupulae and maculae converged on them. A few units received additional visual or proprioceptive information. The homology relationship with a mammalian vestibular thalamic nucleus is discussed briefly.     

Exercise tests before and after heart valve replacement

A simple progressive exercise test was performed before and after operation on five subjects undergoing mitral valve replacement and on five subjects undergoing aortic valve replacement. The responses of heart rate and ventilation were related to work rate )kilopond metres/min). The patients were also assessed clinically by the New York Heart Association grading and radiologically before each exercise test. The clinical grading was shown to be a poor guide to observed exercise tolerance, as the improvement noted in symptoms was not matched by the objective measurement of working capacity. Only two patients had normal exercise tolerance after surgery, although six of the ten patients claimed that they had no exertional dyspnoea after operation. The changes in simple ventilatory function tests before and after operation were generally small. We suggest that measurements of exercise tolerance before and after operation should be an essential part of heart valve replacement surgery.     

NMR evidence against covalent attachment of an aldehyde ''transition-state'' analogue to alpha-chymotrypsin

The growth responses of an acetate-utilizing isolate of Butyrivibrio fibrisolvens to CO2, acetate and pyruvate were determined using a chemically-defined medium. Carbon dioxide was essential for growth and both acetate and pyruvate increased growth. 14C from [I-14C]pyruvate appeared predominantly in formate and lactate. These results, together with those obtained with enzyme preparations, indicated pyruvate synthase, pyruvate-CO2 exchange and pyruvate formate lyase to be active.     

Anticonvulsant drug concentrations in epileptic patients

Using Wistar stain male rats, it has been shown that 2 atmospheric pressures associated with oxygen saturation, together or singly for 90 minutes daily for successive 46 days, resulted in no significant change on the ratio of testes to body weight. No significant change was observed in the incorporation of 3H-thymidine into testes and pituitary glands between the pressure-treated groups and the control group.