Vitamin E, supplemented to semisynthetic or natural commercial diets in amounts of 60–180 mg/kg increased the humoral immune response of mice against sheep red blood cell or tetanus toxoid antigens by 30–40%, measured by the antibody plaque forming cell test, or by hemagglutination. Vitamin E affected particularly the IgG antibody production. The antioxidant NN-diphenyl-p-phenylene diamine was ineffective in restoring immune response in a vitamin E-deficient diet, and was only partially effective in replacing vitamin E in a normal diet.

We investigated the involvement of adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) in adenosine (ADO) receptor-mediated coronary artery relaxation. Rings from left anterior descending coronary artery, with the endothelium mechanically removed, contracted with prostaglandin F2 alpha and relaxed in a concentration-dependent manner to ADO, 2-chloroadenosine (CAD), l-N6-(2-phenylisopropyl)adenosine (R-PIA), and 5'-(N-ethylcarboxamido)adenosine (NECA). These relaxations were blocked by addition of the ADO receptor antagonist 8-(sulfophenyl)theophylline (8-SPT), indicating ADO receptor involvement. In an endothelium-free membrane preparation, ADO, CAD, and R-PIA all stimulated adenylate cyclase activity in a concentration-dependent manner, and these responses were blocked by 8-SPT. The increase in adenylate cyclase activity produced by ADO, CAD, and R-PIA was completely dependent on the presence of guanosine 5'-triphosphate, suggesting G protein involvement. Surprisingly, NECA and CGS-21680 did not increase adenylate cyclase activity. Unlike atrial natriuretic factor, neither NECA, CAD, R-PIA, nor ADO increased guanylate cyclase activity, suggesting that cGMP is not involved in ADO receptor-mediated relaxation. Data presented in this study support the hypothesis that ADO receptor-mediated coronary artery relaxation may involve cAMP; however, the inability of NECA and CGS-21680 to stimulate adenylate cyclase suggests that the ADO receptor-signaling mechanisms in coronary artery may be more complicated than agonist interaction with a single adenylate cyclase-coupled A2 adenosine receptor.

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Media containing antimicrobial agents have been formulated for use as an adjunct to the standard media in an effort to reduce contamination and improve isolation of mycobacteria from clinical specimens. Selective 7H10 (S7H10) was developed for use in the isolation of mycobacteria from undecontaminated material. During a 33-month period, 10,782 clinical specimens were cultured in parallel on S7H10 without decontamination and on 7H11 after treatment with 2% sodium hydroxide-N-acetyl-L-cysteine. Results of this study show the overall contamination rate to be threefold lower on S7H10 than on 7H11 (304 versus 1,000). The number of specimens negative on NaOH-treated, 7H11-cultured specimens and contaminated on S7H10 was 282, whereas that negative on S7H10 but contaminated on NaOH-7H11 was 923. There were 6 positive cultures missed due to contamination on S7H10, compared with 61 on 7H11. Positive cultures on S7H10 outnumbered those on 7H11 by 106. This evaluation of S7H10 shows that it can be used with undecontaminated specimens in conjunction with standard methods and media for isolation of mycobacteria from clinical specimens.