Immunomodulatory activity of 9-(2-phosphonylmethoxyethyl)adenine (PMEA), a potent anti-HIV nucleotide analogue, on in vivo murine models

In order to evaluate the influence of antiviral nucleoside analogues upon the natural immune system, we investigated the immunomodulatory activity of 9-(2-phosphonylmethoxyethyl)adenine (PMEA), a nucleotide analogue with potent anti-HIV and anti-herpes activity, in a murine system. C57BL/6 mice were inoculated intraperitoneally with 10, 25 and 50 mg PMEA/kg. Mononuclear cells were isolated from their spleens, and some natural immune functions were evaluated. The results show that PMEA significantly increases the levels of natural killer (NK)-cell cytotoxicity. We also found that alpha/beta IFN production was substantially increased in PMEA-treated mice, while both IL-1 and IL-2 production was decreased. Thus, PMEA can increase some natural immunity functions, such as NK activity and IFN production. These results suggest that PMEA might be active in vivo against HIV and herpes viruses both as an immunomodulator and as an antiviral compound.

[Cardiovascular involvement and relative risk factors in systemic sclerosis. Personal contribution]

In systemic sclerosis (SS), cardiovascular commitment was recorded in an autopsy series, in widely different percentages, from 12 to 81%. On the other hand, clinical diagnosis of cardiopathy is made in far fewer cases. In addition, the coexistence of renal and/or pulmonary commitment makes difficult separation between primary and secondary heart damage. In 22 patients (2 m, 20 f) aged between 34 and 75 (average 55 +/- 11) with SS, a study has been made of the a) prevalence of cardiovascular commitment; b) the significance of the classic risk factors; c) the erythrocyte filtration time or TF (index of microangiopathic damage). Metabolic stability, fibrinogen, haematocrit and TF (Reid et al. method) were assessed in each patient. Nine patients (40.9%) presented ischaemic cardiopathy (myocardial infarction in three and effort angina in six), one (4.5%) presented hypertensive cardiopathy. Conduction disturbances were observed in five patients (22.7%). Whereas a statistically significant increase in TF was observed in cardiopaths, no differences in plasma levels of glucose, cholesterol or fibrinogen were observed. The incidence of smoking and the familial factor were also insignificant.

[The use of dynamic electrocardiographic monitoring in scleroderma patients]

A comparative analysis of arrhythmias by "basal" electrocardiogram (ECG) and by continuous 24-hour Holter electrocardiogram monitoring was performed in 17 patients with systemic sclerosis (16 women and one man). Our study confirms that rhythm disturbances are better detectable using Holter monitoring. In fact, no patients had ventricular arrhythmias detected by ECG; on the contrary, Holter monitoring revealed ventricular arrhythmias in nine patients (53.3%). This method also revealed a ventricular tachycardia, not detected by ECG. In two patients ventricular repolarisation abnormalities without symptoms was revealed.

Suppressor cells induced by influenza virus inhibit interleukin-2 production in mice

PR8 virus depressed interleukin-2 (IL-2) and natural killer (NK) cell activity in BALB/c infected mice. IL-2 production was not dependent on (i) a decreased number of T cells or (ii) a primary defect in IL-1 production, but on a T-suppressor cell subpopulation. In fact, when T suppressor cells were removed from infected spleen cells, we observed normal levels of IL-2 activity.