peripheral vasodilatation observed in normal subjects; it seems logical, therefore, that acute left ventricular in¬ sufficiency could be treated by producing a diminution in the peripheral resistance. This has been done by Sarnoff, Goodale, and Sarnoff,10 using ganglion-blocking agents. On the other hand, it has been demonstrated that the stimulation of the carotid sinus produces a peripheral vasodilatation u and thus can improve the clinical condition of patients with hypertension and pul¬ monary edema. It should also be mentioned that the bradycardia that almost always is produced by the caro¬ tid sinus reflex permits a better filling in diastole and therefore a better initial length of the cardiac fiber. Per¬ haps all of these factors come into play to produce im¬ provement in these cases.
SUMMARYIn hypertensive patients with acute pulmonary edema or cardiac asthma, the stimulation of the carotid sinus produces a rapid improvement and is accompanied by a drop in pulse rate and blood pressure. In the same type of patients, the recovery period after standard exercise tolerance tests can be considerably shortened if carotid sinus stimulation is applied after the tests.British American Hospital, Apartado 2713 (Dr. Garrido-Lecca).In 1950 one of us (S. O. S.), working with others,1 evaluated the long-term use of folic acid in pernicious anemia, with the eventual observation of both hematological and neurological relapse. Because the natural history of pernicious anemia is characterized by spontaneous exacerbations and remissions, such long-term studies were believed indicated to evaluate critically any new therapeutic agent. With the same premise in mind, we have studied 51 patients treated with parenterally given vitamin B12 therapy, 32 of whom were observed over a period of four years or longer. A similar group, comprising 63 patients with pernicious anemia who were treated with liver extract, was evaluated. Of these, 34 were followed over 4 years, some for as long as 16 years. Again, as in the folic acid study, the clinical course, liver extract requirements, and neurological and hematological status were all well established and stabilized when the study was begun. The dosage of vitamin B12 was generally 30 mcg. every four weeks, and of liver, 30 U. S. P. units every four weeks, except for pa¬ tients with neurological symptoms, in which case more frequent injections were given in both groups. Most of the patients maintained with vitamin B]2 therapy were in good neurological status at the onset of therapy. The pa¬ tients were observed at intervals of one to four weeks for clinical, neurological, and hematological evaluation. The criteria for neurological and hematological relapse were identical to those in the previous report.1 We have also had the opportunity to observe 36 patients who were being treated with combined oral therapy with vitamin B12 and folie acid in the dose of 25 meg. of vitamin B]2 and 1.67 mg. of folie acid in each capsule. The therapy program consisted of capsules, one of which was to be take...