The role of anti-HBs antibody in reducing the probability of hepatitis after accidental exposure to serum from patients with hepatitis or carriers of HBs Ag was studied prospectively among 712 medical workers. One fourth of the workers were anti-HBs positive and less than one per cent of them developed hepatitis, in contrast to 11 per cent among those who were anti-HBs negative. Three coded immune-serum globulin preparations of varying anti-HBs titer were randomly assigned. Among 251 persons passively immunized with globulin having a conventionally low anti-HBs titer, hepatitis developed in 17 (seven per cent) within six months. Comparative rates among those receiving intermediately high titer and high titer globulin, respectively, were five per cent (11 of 208) and two per cent (5 of 253). The significantly lower incidence among the latter (P less than 0.05) was offset by six additional cases, all in recipients of high titer globulin, detected when follow-up was extended to nine months.

A randomized, double-blind, multicenter study of hepatitis prevention by immune serum globulin with high anti-HBs titer ("hepatitis B immune globulin") was carried out among 318 new patients and 296 staff members of renal dialysis units. Three milliliters of high titer globulin, repeated at four months, was compared with equal doses of intermediate or normal titer globulin. Among staff members, the cumulative percentages developing hepatitis or HBs Ag, or both, within eight months were 6.9, 11.7, and 11.1 in the high, intermediate, and normal titer groups respectively. The lower incidence associated with high titer globulin was not significant (P greater than 0.05). However, among the patients the respective percentages were 7.9, 21.3, and 23.1 and the lower incidence in the high titer globulin group was significant.

Because the value of usual immune globulin preparations in preventing Type B hepatitis is doubtful, we carried out a double-blind comparison of a control human immune globulin preparation with one--identified as HBIG--that had a high concentration (442 mug per milliliter) of antibodies to surface components of hepatitis B virus. Effectiveness was tested in spouses of patients with acute Type B hepatitis. Within 150 days after injection, nine of 33 spouses in the control group had symptomatic Type B hepatitis, compared with one of 25 spouses receiving HBIG. One non-B case also occurred in the HBIG group. Five control globulin recipients had evidence of subclinical hepatitis B infection, compared with one HBIG recipient. Thus, HBIG appeared effective in suppressing not only disease, but also infection itself. Prophylactic value has been demonstrated in persons who should now be recognized as being at exceptionally high risk.

Nitroglycerin has been shown to reduce ST-segment elevation during acute myocardial infarction, an effect potentiated in the dog by agents that reverse nitroglycerin-induced hypotension. Our study was designed to determine the effects of combined nitroglycerin and phenylephrine therapy. Ten patients with acute transmural myocardial infarctions received intravenous nitroglycerin, sufficient to reduce mean arterial pressure from 107 +/- 6 to 85 +/- 6 mm Hg (P less than 0.001), for 60 minutes. Left ventricular filling pressure decreased from 19 +/- 2 to 11 +/- 2 mm Hg (P less than 0.001). SigmaST, the sum of ST-segment elevations in 16 precordial leads, decreased (P less than 0.02) with intravenous nitroglycerin. Subsequent addition of phenylephrine infusion, sufficient to re-elevate mean arterial pressure to 106 +/- 4 mm Hg (P less than 0.001) for 30 minutes, increased left ventricular filling pressure to 17 +/- 2 mm Hg (P less than 0.05) and also significantly increased sigmaST (P less than 0.05). Our results suggest that addition of phenylephrine to nitroglycerin is not beneficial in the treatment of patients with acute myocardial infarction.

Because photodynamic inactivation of herpes simplex virus infections may not be free of hazard, the efficacy of photodynamic inactivation with neutral red and light was evaluated in a placebo-controlled study of 170 episodes of recurrent herpes simplex virus infection in 96 patients. The preparation of neutral red that was used was shown to photoinactivate herpes simplex virus in vitro, but had no significant effect on the rate of resolution of herpetic lesions (P greater than 0.10) or on the frequency of subsequent recurrences (P greater than 0.10), except for orolabial lesions, in which an adverse effect on the rate of subsequent recurrences was observed (P less than 0.05). In the absence of demonstrated efficacy, the routine use of neutral red and light in patients with recurrent herpes simplex virus infections should be discontinued. Furthermore, other photoactive dyes should not be used until their efficacy has been demonstrated by suitably controlled clinical trials.

Anecdotal accounts suggested that smoking marihuana decreases the nausea and vomiting associated with cancer chemotherapeutic agents. Oral delta-9-tetrahydrocannabinol was compared with placebo in a controlled, randomized, "double-blind" experiment. All patients were receiving chemotherapeutic drugs known to cause nausea and vomiting of central origin. Each patient was to serve as his own control to determine whether tetrahydrocannabinol had an antiemetic effect. Twenty-two patients entered the study, 20 of whom were evaluable. For all patients an antiemetic effect was observed in 14 of 20 tetrahydrocannabinol courses and in none of 22 placebo courses. For patients completing the study, response occurred in 12 of 15 courses of tetrahydrocannabinol and in none of 14 courses of placebo (P less than 0.001). No patient vomited while experiencing a subjective "high". Oral tetrahydrocannabinol has antiemetic properties and is significantly better than a placebo in reducting vomiting caused by chemotherapeutic agents.

We conducted a double-blind study to determine the efficacy of 17alpha-hydroxyprogesterone caproate in preventing premature delivery in 43 high-risk patients. Premature delivery did not occur in 18 patients receiving the progestational agent, whereas 41 per cent of the 22 receiving the palcebo had premature delivery (P less than 0.01). The mean duration of pregnancy and the mean birth weight in the former group (38.6 weeks +/- 1.6 S.D., and 2836 g +/- 412 S.D.) were both significantly greater (P less than 0.025) than that in the latter (35.2 weeks +/- 6.7 S.D.; 2361 g +/- 1085 S.D.). The perinatal mortality rate in the group given the progestational agent (O per cent) was significantly less than that observed in the placebo group (27 per cent) (P less than 0.05). Although there were no complications attributable to the progestational drug, the study population was too small for assessment of immediate or long term safety. However, the results indicate a possible obstetric use for this drug.

Pneumonia caused by Pseudomonas aeruginosa occurs frequently in critically ill patients and is associated with a mortality rate of 70 per cent. An aerosol of polymyxin B was administered (2.5 mg per kilogram per day) to the upper airways of 292 patients in a respiratory-surgical intensive-care unit during a seven-month period, in an attempt to prevent Ps. aeruginosa pneumonia. Although only one of the patients studied acquired pneumonia due to Ps. aeruginosa, 10 others acquired pneumonia caused by a polymysinx-resistant organism. Seven pneumonias were caused by organisms not frequently pathogenic to man (flavobacteria, serratia and Streptococcus faecalis). The mortality rate for acquired pneumonia in this study, 64 per cent, is greater than that in previous studies in which either no polymyxin or cyclic polymyxin therapy was used. Continuous use of polymyxin B aerosol appears to be a dangerous form of therapy.

Effects on anginal symptoms of sudden withdrawal of large doses of propranolol or placebo were evaluated in 20 patients in a double-blind crossover efficacy trial requiring sudden cessation of the agent. With propranolol, 160 to 320 mg per day for six and 12 weeks, no patients had increased angina or nitroglycerin use, and there were no hospitalizations or deaths. However, within two weeks of discontinuance of propranolol, untoward ischemic events developed in 10 patients. Six had serious withdrawal complications: intermediate coronary syndrome in three, and ventricular tachycardia, fatal myocardial infarction, and sudden death in one each. In four patients discontinuance of placebo increased anginal symptoms; in the remaining 10, ischemic symptoms were not provoked. The rebound phenomenon was related to degree of pre-propranolol angina and relief of pain by the agent. Thus, chronically administered propranolol should be gradually reduced, and activity restricted during its withdrawal.

Forty patients, randomly assigned to an experimental and a control group, participated in a double-blind study to assess the effectiveness of acupuncture in reducing chronic pain associated with osteoarthritis. The experimental group received treatment at standard acupuncture points, and the control group at placebo points. Analysis before and after treatment showed a significant (P less than 0.05) improvement in tenderness and subjective report of pain in both groups as evaluated by two independent observers and in activity by one observer. Comparison of responses to treatment between the two groups showed no significant (P greater than 0.05) difference. Thus, both experimental and control groups showed a reduction in pain after the treatments. These results may reflect the natural course of illness, and various attitudinal and social factors.

Cimetidine, a non-thiourea-containing H2-receptor antagonist, was studied in seven patients with duodenal ulcer. Oral doses of 100, 200, and 300 mg were tested. Each dose significantly inhibited basal and meal-stimulated secretion. After 300 mg, basal acid secretion was essentially zero for at least five hours. The meal-stimulated three-hour acid output after the 300-mg dose was reduced by 67%. Cimetidine, 300 mg, decreased meal-stimulated acid secretion significantly more than an optimal effective dose of propantheline bromide (P less than 0.05). Inhibition of meal-stimualted gastric acid secretion showed a significant relation to peak blood cimetidine concentration (r is equal to 0.76, P less than 0.01). Cimetidine did not affect meal-stimulated gastrin release. No toxicity was observed after serial doses given during these tests. Cimetidine may be useful in treatment of acid-peptic diseases provided no important toxicity appears on chronic testing.

The electrocardiographic response to exercise was compared with the results of coronary angiography in 89 patients with Type II hyperlipoproteinemia who had previous myocardial infarction or typical angina or both (43 patients)(Group A), "atypical angina" (16 patients)(Group B)or positive electrocardiographic response to exercise without other evidence of cardiac disease (30 patients)(Group C). Thirty-nine of 43 in Group A had greater than or equal to 50 per cent stenosis, and 26 (67%) of these 39 had negative exercise tests. In Group B, five of the 16 had greater than or equal to 50% stenosis, and three had positive exercise tests (one patient had a false-positive test). In Group C, eleven of 30(37%) had greater than or equal to 50% stenosis; however, nine (30%) had minor stenosis (less than or equal to 50%), and 10(33%) normal coronary arteries. The diagnostic usefulness of exercise electrocardiography is limited. False-negative responses are frequent in patients with clinically suspected coronary disease, and false-positive responses frequent in asymptomatic patients.