[Ascites inaugurating systemic mastocytosis (author's transl)]. / Ascite révélatrice d'une mastocytose cutanéo-viscérale.

The authors report a case of urticaria pigmentosa with systemic mastocytosis and review the literature on this occasion. The onset of the disease was marked by the development of ascites. Ascites is rarely mentioned in this affection and remains, as with other manifestations of systemic mastocytosis, without any explanation. The diagnosis was established first on the diffuse mastocyte-infiltration especially in the bone-marrow and second, on the hypersecretion of hormonal factors especially histamine by mastocytes. The symptomatic treatment of this affection is based on histamine inhibitors and disodium cromoglycate seems to be an efficient drug. With the possible development of acute leukemia, the eventual association with a carcinoma and the frequency of serious digestive bleeding, the prognosis may be very poor.

Release of 1-O-alkylglyceryl 3-phosphorylcholine, O-deacetyl platelet-activating factor, from leukocytes: chemical ionization mass spectrometry of phospholipids.

Evidence is presented for the simultaneous release of platelet-activating factor (PAF-acether) and of its deacetylated derivative (lyso-PAF-acether) from hog leukocytes. On the basis of spectroscopy and chemical reactions, the structure of O-deacetyl-PAF is shown to be 1-O-alkylglyceryl 3-phosphorylcholine, an alkyl ether analog of lyso-phosphatidylcholine. Acetylation of lyso-PAF yields a compound with biological activity and chromatographical behavior indistinguishable from those of native PAF. Lyso-PAF may be considered to be either the precursor or the enzymatic degradation product of PAF. The usefulness of chemical ionization mass spectrometry for structural determination of phospholipids is also demonstrated.

Nosiheptide, a sulfur-containing peptide antibiotic isolated from Streptomyces actuosus 40037.

Nosiheptide (9671 R.P.) isolated from Streptomyces actuosus 40037 (NRRL 2954) is a sulfur-containing polypeptidic antibiotic, quite different from all the other members of this family. Very active in vitro against gram-positive bacteria, it is inactive in vivo in experimentally infected mice. Not toxic, even at high dose, it may be used as a feed additive for chickens and pigs and it shows a favourable effect on the growth and conversion index.

Emericid, a new polyether antibiotic from Streptomyces hygroscopicus (DS 24 367).

Emericid is a new polyether polycyclic ionophore antibiotic excreted by Streptomyces hygroscopicus (DS 24 367). Active in vitro against Gram-positive bacteria, it is ineffective in vivo. At a 0.006-0.02% level in the diet it protects chickens and rabbits against coccidiosis.

Double-stranded ribonucleic acid from Mengo virus: production, characterization, and interferon-inducing and antiviral activities in comparison with polyriboinosinic-polyribocytidylic acid.

Mengo virus double-stranded ribonucleic acid (dsRNA) was obtained on a semi-industrial scale from infected cultures of BHK-21 cells grown in suspension. Yield of the extraction and purification operations was small (about 22 mg from 10(11) cells in a 100-liter culture). Physicochemical characterization of this dsRNA gave an estimated molecular weight close to 4 x 10(6), a density of 1.59 (similar to that of the poliovirus dsRNA), and a thermal transition midpoint of 94 C. This product was a little more toxic for the mouse, by the intravenous route, than polyriboinosinic . polyribocytidylic acid (poly I:C) and strictly comparable in this respect to poliovirus dsRNA. The interferon-inducing capacity in the mouse and the antiviral activities in the mouse (infected with encephalomyocarditis, Semliki Forest, influenza, foot-and-mouth disease, and murine hepatitis viruses) and in the rabbit (Shope fibroma virus) of the ultraviolet light-inactivated product were practically identical, on a quantitative basis, with those of poly I:C. In vitro and in vivo experiments showed the dsRNA from Mengo virus to be slightly but significantly more resistant than poly I:C to the inactivating effect of human serum.