Preparation and Properties of a Small-Particle Aerosol of Coxsackie A21

Abstract

818COXSACKIE Azl AEROSOL Rowever, the available data are merely suggestive and further experiments are needed to prove this supposition. If this hypothesis is correct, adrenalectomy (with substitution for lack of mineral corticoids) should increase the incidence of non-thymic lymphomas in neonatally thymectomized hosts.The incidence of myeloid leukemias was markedly increased by thymectomy in our earlier experiment( 1) and in those by Gross (12). In the present experiment only one case of myeloid leukemia was found in 106 thymectomized virus-infected rats. It occurred in a thymectomized rat with an implanted empty Millipore chamber. The lower incidence of myeloid leukemia in the present experiment (less than 1%) compared with 12% in our earlier experiment (1) is puzzling. We expected a higher incidence because more rats escaped early deaths from non-thymic lymphomas (cf. 6 ) . Failure of thymectomized rats to develop myeloid leukemia in the present experiments may be explained by low concentration of the virus. The thymus is a favored organ for replication of the virus ( 2 ) . If so, neonatal thymectomy prior to virusinfection as done in the present experiments, eliminates this effect of thymus and neonatally thymectomized rats might be expected to have less virus than rats infected with virus first and thymectomized one month later. month after virus-infection( 1 ) originated in cells which have been transformed in the thymus and seeded in other lymphoid organs prior to thymectomy. 3. The data also suggest a) that non-thymic lymphomas may be induced by the virus and b) that stressful agents which cause corticoid discharge might lower not only the incidence of the thymic, but also the non-thymic lymphomas.We acknowledge the able assistance of Miss Sandra

Inactivation of Virus-Containing Aerosols by Ultraviolet Germicidal Irradiation

“…When a virus is encased in a droplet, its infectivity is enhanced because of shielding from drying, temperature, and sunlight (Tyrrell 1967). It was indicated that virus-containing aerosols less than 2 µm in size have higher infectivity than those of the virus itself (Couch et al 1965). From the previous studies (Buckland et al 1962;Couch et al 1965;Benbough 1971), virus-containing aerosols were generated by Collison three-jet nebulizer to range from 0.5 µm to 3.0 µm.…”

Production of Illness with a Small-Particle Aerosol of Coxsackie A21*

“…Studies in chambers with controlled humidity indicate that similar aerosol particles increase in size by as much as 2.0 to 2.5 times when exposed to 90%o relative humidity (5). If the virus were contained in particles 3 u in diameter, about 40% would be removed in the nasal passages and tracheobronchial tree, and deposition in the pulmonary lobules would fall appreciably (2,3).…”

“…It is thus possible to estimate with some accuracy both the site of viral deposition and the amount of virus deposited when aerosols of known particle size containing known amounts of virus are inhaled. Therefore, when preliminary studies demonstrated the feasibility of the use in human volunteers of a small-particle aerosol containing Coxsackie A21 virus (4), and the properties of the aeorsol had been determined (5), observations were made on the response of volunteers to graduated doses of the aerosol utilizing three different inocula of Coxsackie A21.…”

An adhesive surface sampling technique for airborne viruses

“…In contrast, the present author found in a similar drum experiment that 81 % of the virus aerosol collected was retained on the last stage of the sampler. Couch et al (1965) sampled virus aerosols, from a Collison spray, on gelatin layered on agar (total volume 27 ml. ), in an Andersen sampler from aerosol apparatus similar to that used by the author.…”

“…Both of these samplers have been used previously to collect airborne virus. Samples were collected on agar followed by washing (Vlodavets, Gaidamovich & Obukhova, 1960;Jensen, 1964) and on gelatin followed by liquefaction (Dahlgren, Decker & Harstad, 1961;Kuehne & Gochenour, 1961;Couch et al 1965;Gerone et al 1966;Wolfe, Greisemer & Farrell, 1968;Rechsteiner, 1968). It was suspected that loss of viable virus could take place due to inefficient washing.…”