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The successful use of diuretics depends upon a knowledge of their mode of action, their potency, and their side-effects. The four basic groups of diuretics which cover most situations are: (i) the thiazides, (ii) ethacrynic acid or frusemide, (iii) spironolactone or triamterene, (iv) mannitol.

The fall in blood base occurring after the administration of secretin and the aspiration of duodenal contents was assessed in normal patients and in patients with chronic pancreatitis. In contrast to normal patients, those with chronic pancreatitis showed only a small fall or no fall in blood base level. There was no correlation between the amount of bicarbonate as determined by aspiration and that calculated from the blood base change. In 3 normal patients the magnitude of the renal compensatory mechanism in the post-secretin hour was found to be insignificant.

In 30 patients with acute myocardial infarction complicated by either advanced atrioventricular or bundle branch block, pulmonary arterial wedge pressures were studied in relation to clinical and radiographic features of left ventricular failure, changes in central venous and pulmonary arterial pressures, and arterial hypoxemia. An increase in mean pulmonary arterial wedge pressure was poorly correlated with the presence of dyspnea, audible third or fourth heart sounds, or persistent basal rales; however, it was significantly related to radiographic evidence of pulmonary venous dilatation or edema, a systolic blood pressure of less than 100 mm Hg, gallop rhythm associated with tachycardia, and heart rate in patients with sinus rhythm and normal atrioventricular conduction. Increased mean right atrial pressure indicated increased mean pulmonary arterial wedge pressure in patients with isolated anterior infarction, but in several patients with isolated inferior infarction the level of right atrial pressure was disproportionately high. The pulmonary arterial diastolic pressure closely reflected the mean pulmonary arterial wedge pressure in the absence of obstructive airways disease or pulmonary embolism. The level of the arterial oxygen tension fell as the mean pulmonary arterial wedge pressure rose, but it was considerably reduced in some patients with only moderately increased pressures. However, the latter usually had radiographic evidence of pulmonary venous dilatation or edema, suggesting that the pressure had been elevated previously to higher levels.

The kidneys form urine by filtering about 180 litres of filtrate daily and by reabsorbing about 99 % of this filtrate in the tubules. The proximal tubules account for the majority of this reabsorption (60 to 70 %), and the loops of Henle, the distal tubules and the collecting ducts for the rest. The ability of the kidney to form concentrated urine depends upon the pumping of sodium out of the ascending limb of the loop of Henle into the medulla, to form an hypertonic interstitium. In the presence of anti-diuretic hormone (ADH), water is reabsorbed from the collecting ducts as they traverse the hypertonic medulla. Dilute urine is formed by the reabsorption of sodium in the ascending limb of the loop of Henle, and by the passage of this dilute filtrate through the impermeable collecting ducts in the absence of ADH. Potassium and hydrogen ions are exchanged for sodium reabsorbed in the distal tubule under the control of aldosterone.

The ventilatory responses to CO2 without hypoxia, to hypoxia at constant PAACOACO2 and to CO2 combined with hypoxia were measured in duplicate with an interval of 20 min. between the two sets of measurements. The PAACOACO2 threshold during the second set differed in only random fashion from that during the first set; so did the CO2 sensitivity in the absence of hypoxia. The CO2 sensitivity during hypoxia, however, was significantly greater during the second set of measurements. The relevance of these results to the investigation of drugs which affect respiration is discussed.

The effect of ethamivan (vanillic acid diethylamide) on the ventilatory response to carbon dioxide has been investigated in healthy young adult males. Intravenous infusion of the drug at a rate of 9 mg/min causes respiratory stimulation depending in degree upon the prevailing alveolar CO(2) tension. When the latter is low stimulation by the drug is most marked and may largely support respiration below the CO(2) threshold. As alveolar Pco(2) increases, the effect of the drug disappears. These findings are discussed.

A 49-year-old man with liver disease developed a unilateral telangiectatic lesion over the left trigeminal and left C3, C4, C5, and T1 dermatomal areas. This case fulfills the criteria for unilateral nervoid telangiectatic syndrome (UNTS), and as such represents the 11th reported case of UNTS and the first case, to our knowledge, of visceral involvement associated with a similar vascular malformation. A hemorrhagic tendency is present in this syndrome when there is gastrointestinal involvement.

The ventilatory effects of intravenous injections and infusions of prethcamide have been investigated with healthy young adult male volunteers. Ventilatory changes due to the drug were measured at constant inspired Pco2 or constant alveolar Pco2, and in relation to the response to changes in alveolar Pco2. The experiments show that the drug is a mild and somewhat inconstant respiratory stimulant, slow and prolonged in action and liable to give rise to a variety of unpleasant side-effects.

A method is described for recording alveolar CO2 tension using simple and inexpensive apparatus. The changing state of hyperventilation due to CO2 has been studied and a procedure devised for deriving the steady-state CO2-response line from data obtained during the changing state. This procedure has considerable practical advantages over conventional methods. Evidence is presented to show that the time needed for equilibration of CO2 between the arterial blood and the cells of the respiratory centre is of the order of 4 min.

The hemodynamic changes associated with complete heart block complicating acute myocardial infarction and the effects of artificial pacing at various rates on these measurements were studied in 13 patients. Studies were performed on the first day of complete block in all patients and were repeated on subsequent days in six. With two exceptions cardiac output was increased by pacing. In patients paced at progressively increasing ventricular rates, the rate associated with the maximal cardiac output exceeded 100/min, with one exception. However, an adequate response usually occurred between 80 and 90/min. Stroke volume fell as the rate was increased with pacing in most patients, but rose in some, suggesting improved myocardial performance. Systemic blood pressure increased, and the change paralleled cardiac output changes fairly closely as pacing rates were increased. The blood pressure did not, however, reflect reliably the absolute level of cardiac output either in heart block or after the return of sinus rhythm. Systemic vascular resistance was high in most patients with low cardiac outputs and fell with pacing at maximal output rates. There was no consistent change in mean right atrial or mean pulmonary arterial pressure with pacing during the period of study. Tension time index was low in heart block, and increased considerably with pacing, implying a corresponding increase in myocardial oxygen requirements. Pacing improved signs of depressed mental function and poor skin circulation which were invariably associated with a severe reduction in cardiac output. These signs were found to be superior to heart rate and blood pressure in clinical evaluation of the adequacy of the cardiac output in heart block and the response to pacing.

Excerpt To the editor: I would like to draw attention to a possible relation between Feldman and Hershfield's paper (1) and a recent paper by Schiefer, Gee, and Ward (2). Both deal with a peculiar ...

A 49-year-old man with liver disease developed a unilateral telangiectatic lesion over the left trigeminal and left C3, C4, C5, and T1 dermatomal areas. This case fulfills the criteria for unilateral nevoid telangiectatic syndrome (UNTS), and as such represents the 11th reported case of UNTS and the first case, to our knowledge, of visceral involvement associated with a similar vascular malformation. A hemorrhagic tendency is present in this syndrome when there is gastrointestinal involvement.

To the Editor.— Penile nodulocystic lesions are rarely mentioned in standard dermatologic texts. Reports of the occurence of such lesions are also rare in the dermatologic literature. The purpose of this report is to describe a patient with a urethral diverticulum, an entity that to our knowledge has not been described previously in recent dermatologic literature. Report of a Case.— A 16-year-old uncircumcised youth came to the Dermatology Clinic for evaluation of a urethral discharge of three day's duration and a penile mass. The penile lesion was said to have been present for approximately three years. It did not change in size with micturition, although the patient did have symptoms of recurrent mild urethritis. The patient denied having had previous urologic instrumentation or neurologic dysfunction. Physical examination showed there was a yellow-green, purulent urethral discharge. A Gram stain of the discharge disclosed numerous Gramnegative intracellular diplococci compatible with Neisseria gonorrhoeae

To the Editor.— While practicing in Yuma, Ariz, I have seen two patients in the last six months who presented with pulled rectus abdominal muscle insertions over the symphysis pubis. Careful questioning of both patients revealed no history of trauma, but both patients had experienced antecedent, prolonged paroxysms of coughing. Both these patients, following evaluation, had pulmonary coccidioidomycosis confirmed by skin tests, x-ray films of the chest, and serum titers. I feel these patients demonstrate the importance of careful evaluation of possible pulmonary disease in patients with isolated pulled rectus abdominal muscles as their presenting complaint.