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R C Stewart

Publications and source records attributed to R C Stewart.

51 records · Page 3Linked to original sources

Growth characteristics of two rhinovirus strains in WI-26 and monkey kidney cells.

Haff, R. F. (Smith Kline & French Laboratories, Philadelphia, Pa.), B. Wohlsen, E. E. Force, and R. C. Stewart. Growth characteristics of two rhinovirus strains in WI-26 and monkey kidney cells. J. Bacteriol. 91:2339-2342. 1966.-Viruses with 1059 and HGP serotype and with human and monkey host range characteristics, respectively, were employed. Adsorption kinetics of the 1059 and HGP strains to WI-26 cells, and HGP to Green African monkey kidney cells (MKC), were similar. Fifty per cent of the virus was adsorbed to cell monolayers within 10 min; adsorption was essentially complete by 2 hr. The 1059 strain failed to adsorb to MKC, at least to an appreciable extent. Lack of receptors for adsorption of 1059 accounts for the inability of this cell to support multiplication of the virus. It is probable that MKC are refractory to infection with other H strains of rhinovirus for the same reason. Single-step multiplication cycles have been described for the HGP strain in WI-26 and MKC cultures and for the 1059 strain in WI-26 cells. In both cells, HGP exhibited a latent period of 7 hr. Increase of intracellular and cell-associated virus appeared somewhat prior to that of extracellular virus. Maximal titers were attained by 9 to 10 hr. In contrast, initial increase of 1059 in WI-26 cells occurred after 10 hr. Titer rose to peak level 15 hr after infection. Yield of 1059 in WI-26 cells was also fivefold lower than that of HGP in either cell system.

Adsorption↗

Evaluation of bone scan by scintigraphy to detect subclinical invasion of the mandible by squamous cell carcinoma of the oral cavity.

A prospective study using scintigraphy was performed to compare the sensitivity of the Panorex roentgenogram and the bone scan in detecting subclinical invasion of the mandible by squamous cell carcinoma of the oral cavity and floor of the mouth. Twenty-five patients with squamous cell carcinoma of the floor of the mouth were evaluated preoperatively by both the Panorex and scintigraphic techniques and the results compared with postoperative pathologic findings. In 13 (52%) of the cases, Panorex and scintigraphic techniques were comparable in detecting tumor involvement in bone. In eight cases (32%) all three modalities had normal pathologic indications of the mandible. However, in four cases (16%) results of the scintigraphic techniques were abnormal and the Panorex, normal. In four separate cases, the extent of lesion demonstrable by scintiscanning was greater than delineated by Panorex; surgical specimen confirmed this finding. Pathologic examination of operative specimens confirmed tumor involvement. These data lead us to believe that the scintigraphic techniques may be more sensitive in detecting early mandibular involvement with squamous cell carcinoma than the Panorex technique and may help alter the therapeutic approach.

Adult↗