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Two hundred and nineteen (33 GH, 21 GH-PRL, 38 PRL, 16 ACTH, 1 TSH cell functioning and 38 FSH-LH, 17 alpha-chain, 8 mixed, 27 minimal glycoprotein--MIN-GLYC--, 11 small argyrophil granule--SAG--, 4 silent TSH-sTSH--and 5 silent ACTH-sACTH--cell nonfunctioning) adenomas were investigated immunohistochemically with antibodies against ACTH, GH, PRL, TSH, FSH, LH alpha-hCG, chromogranin A (CgA) and chromogranin B (CgB). For immunostaining of CgB a novel monoclonal (B 11) antibody was employed. All types of adenomas were positive for CgB. CgA was widely expressed in nonfunctioning FSH-LH, MIN-GLYC, SAG, MIXED, alpha-chain adenomas and in the single TSH cell functioning adenoma. CgA was lacking both in PRL and ACTH functioning adenomas and was poorly expressed in GH and GH-PRL functioning adenomas. The distribution of Grimelius' silver paralleled that of CgA-IR, but not that of CgB-IR. We conclude that: 1) CgB may be considered as an universal granular marker for pituitary adenomas, 2) CgA is an important marker for nonfunctioning adenomas, 3) the pattern of distribution of CgA and CgB for most nonfunctioning ("null cell" according to Kovacs et al.) adenomas favors their origin from glycoprotein producing (FSH/LH, TSH) cells.

Tryptophan and nonesterified fatty acids (NEFA) are bound to serum albumin. NEFA displace tryptophan from their binding sites. Since NEFA decrease during phototherapy, we examined reciprocal variations of NEFA, total and free tryptophan in jaundiced newborn infants during phototherapy. After 24 h of phototherapy, we noticed a significant decrease of both NEFA and free tryptophan (p less than 0.001). Free tryptophan variations might affect the synthesis of cerebral neutrotransmitter 5-hydroxytryptamine, which depends on the passing of free tryptophan through the blood-brain barrier.

The right ventricular epicardial ventricular fibrillation threshold (VFT) was determined during paced supraventricular rhythm using 100 Hz trains of stimuli at 15 min intervals in dogs before and during the intravenous administration of encainide, a new antiarrhythmic drug. With each VFT determination, simultaneous blood samples were obtained for determination of drug concentration. In 6 control dogs, VFT determined every 15 min during a 210 administered as a 90 min intravenous infusion at three successive rates (0.01, 0.02 and 0.04 mg/kg/min) for 30 min each. VFT measured at 5 and 20 min of each infusion increased from a mean control of 11.5 +/- 1.5 (+/-SE) to 20.2 +/- 2.2 mA (p less than 0.01) after 20 min of the third infusion. The maximal effect occurred during the second infusion with plasma concentration of 594 +/- 46 ng/ml and then reached a plateau. In group II (n = 6), encainide was administered in four successive sequences, each one including a bolus loading intravenous dose followed by a 45 min intravenous infusion. VFT measured at 30 and 45 min of each infusion when the encainide plasma concentration was close to a steady state increased significantly (p less than 0.01) after the second infusion from 11.8 +/- 2 to 27.3 +/- 4 mA. Two dogs in group II developed transient complete atrioventricular block at an encainide plasma concentration of greater than 800 ng/ml. These results show that the new antiarrhythmic drug encainide increases the VFT in anesthetized dogs.