Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: The influence of serotonin (5-hydroxytryptamine) on human detrusor and on pig detrusor, trigone, bladder neck and urethral smooth muscle was explored in a series of in vitro experiments. Serotonin evoked a dose-dependent and reversible contraction of the detrusor. The reverse response was triggered in trigone, bladder neck and urethral smooth muscle--a dose-dependent and reversible relaxation. The maximum amplitude of this relaxation was 85 +/- 15% of the relaxation produced by electrical nerve stimulation. The effect of serotonin was unaltered by blockade of ganglia, alpha- and beta-adrenergic receptors, cholinergic receptors and prostaglandin synthesis. The serotonin antagonists ketanserin, methysergide and cyproheptadine partly inhibited the effect of serotonin. The antagonism differed in potency on strips of different origin. The antagonists were ineffective or minimally effective in blocking responses to nerve stimulation. The effect of serotonin was probably mediated by specific serotonin receptors different from the serotonin-S2-receptors predominating in vascular smooth muscle. Serotonin is a potential neurotransmitter in lower urinary tract smooth muscle, but its importance in micturition physiology and pathophysiology is unknown.
Influence of serotonin on lower urinary tract smooth muscle in vitro.

Abstract: Many patients with diffuse malignant pleural mesothelioma have dyspnea or chest pain. Cardiac symptomatology is frequently difficult to differentiate from symptoms of pleuropulmonary disease. To better define the clinical characteristics of cardiac involvement in patients with mesothelioma, the electrocardiographic (EKG) and echocardiographic findings in 64 patients with biopsy-proven malignant pleural mesothelioma were reviewed. A total of 19/64 (30%) patients had autopsy studies available for review. The EKG was abnormal in 55 patients (89%). Over half (60%) had an arrhythmia, including sinus tachycardia (42%), premature atrial and ventricular contractions (13%), atrial fibrillation (3%), and atrial flutter (1%). Over one third (37%) had a conduction abnormality, including bundle branch block (13%), hemiblock (8.5%), and incomplete right bundle branch block (13%). Echocardiography revealed a total of 13 patients with pericardial effusions, two with pericardial thickening, and one with an anterior sonolucent space. Of 19 autopsies, cardiac invasion was found in 14 (74%), with more than half to the pericardium and more than one quarter to the myocardium. It is concluded that: clinical cardiac abnormalities occur in the great majority of patients with malignant pleural mesothelioma, pathologic cardiac invasion occurs in the great majority of patients with pleural mesothelioma, and the EKG and echocardiogram are helpful in differentiating cardiac involvement from progressive pulmonary disease in patients with pleural mesothelioma.
Cardiac abnormalities in patients with diffuse malignant pleural mesothelioma.

Abstract: The kinetics of caffeine elimination were followed in a ten month old female acutely intoxicated on a street form of the drug. Urine drug screening by gas chromatography-mass spectrometry also showed the presence of ephedrine, phenylpropanolamine, caffeine, theophylline and theobromine. Blood analyses using high pressure liquid chromatography gave evidence for the presence of theobromine, theophylline, caffeine and 1,7-dimethylxanthine. Sequentially taken blood samples determined that the initial stage of caffeine elimination was nonlinear. The Vmax = 27.6 micrograms/ml/hr and Km = 284.6 micrograms/ml. At a plasma level of approximately 30 micrograms/ml the elimination became first order with ke = 0.097 hr-1 and t 1/2 = 7.1 hr. The metabolic generation of theophylline and its elimination were also studied. Theophylline ke = 0.069 hr-1 and t 1/2 = 10.0 hr. Elimination of both drugs was anomalously long for a child of this age.

Toxicokinetics of caffeine elimination in an infant.

