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SUMMARYA revised nomenclature for the polypeptides of respiratory syncytial (RS) virus has been devised on the basis of comparison of the Long, A2 and RSN-2 strains by slab-gel electrophoresis. Seven polypeptides, now designated VP200, VGP48, VPN41, VPP32, VPM27, VP25 and VP10, were observed in preparations of all three strains of RS virus, irrespective of the host cell of origin. In addition, a slowly migrating glycopolypeptide GP 1 was prominent in partially purified RS virus of the Long and A2 strains obtained from Hep-2 cells, and to a lesser extent from BS-C-1 cells. In the case of the RSN-2 strain, this polypeptide was only resolved clearly in virus obtained from Hep-2 cells. GP1 was an atypical glycopolypeptide in that 35S-methionine incorporation was poor relative to 3H-glucosamine incorporation.The ts mutants of RS virus exhibited four distinct phenotypes with respect to intracellular polypeptide synthesis and antigen production at 39 °C. Mutants ts 17 (complementation group B') and ts 19 (group E) were almost completely restricted, suggesting defective early functions. Mutants ts A 1 (group A), ts A7 (group C) and ts 1 (group D) synthesized antigen and polypeptides normally, but the amount of antigen at the cell surface was reduced, suggesting maturation defects. In addition, the VPP32 of ts l (group D) exhibited an aberrant mobility, confirming its viral specificity. The remaining mutants, representing groups B, F and G exhibited generally impaired synthesis at 39 °C.Absence of surface filaments in ts mutant-infected cells at 39 °C confirmed their virus-specific nature.

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entity; Harkness, in his classic monograph, names more than 50 conditions known to cause urethritis.8 One of these is postdysenteric Reiter's syndrome. The situation is obviously confusing, and your leading article (14 August, p. 386) carefully avoided the textbook statement that Reiter's syndrome is usually a complication of venereally acquired non-gonococcal urethritis. Nevertheless, in the statement that the incidence of the disease is estimated at about 1 /,, of the patients with nongonococcal urethritis it perpetuates the textbook teaching without mentioning any of the discordant facts. A pedantic approach is often necessary to make a difficult subject intelligible to students; it is unfortunate that this sometimes carries over into scientific thought and clinical practice.-I am, etc.,

Rift Valley fever virus (RVFV) grown in vero cell cultures has a completed replication cycle within 13 hours. The first signs are the appearance of intranuclear fibrillar rods, followed by aggregations of precursor viral material in host cell cytoplasm and viral nucleocapsids budding into vacuoles associated with the Golgi apparati. Mature particles, liberated by the disintegration of vero cells, contained ribosomelike structures within the nucleocapsid, which was surrounded by a typical unit membrane through which were inserted some 350-375 surface spikes whose inner ends were incorporated into the nucleocapsid structure. In the negatively stained material, the overall diameter of the virion was 90-110 nm; the spikes were 10-18 nm in length and 5 nm in diameter.