No abstract

One hundred fifty-two blood specimens, largely from immunocompromised patients, were collected in heparinized Vacutainer tubes and divided into paired aliquots of equal volume. Buffy-coat preparations, containing mixed leukocyte and separate mononuclear and polymorphonuclear leukocyte populations were obtained by treatment of blood with conventional and Ficoll-Paque/Macrodex (F-P/M) methods. The development of cytopathic effect in monolayers of WI-38 fibroblasts inoculated with cell suspensions derived from the two methods was used to assess virus infectivity. Twice as many virus isolations were obtained using F-P/M. Of those viruses isolated by both conventional and F-P/M, the development of cytopathic effect was more extensive using the latter method. Moreover, a greater variety of viruses was isolated using F-P/M method, as compared to the conventional method. The F-P/M method is no more time consuming than conventional procedures, is readily adaptable for use in the diagnostic virology laboratory, requires only minimal additional cost, and is a particularly suitable and effective means of monitoring viremia.

Restriction endonuclease analysis of purified viral DNA was used to study the molecular epidemiologic characteristics of cytomegalovirus infection in 18 patients having bone marrow transplantation. Four patients who had had asymptomatic excretion of cytomegalovirus in urine before transplantation subsequently developed a cytomegalovirus infection after transplantation (pneumonia in 2 patients, fever and viremia in 1 patient, and asymptomatic viruria in 1 patient). In each patient, the infection that developed after transplantation was caused by a cytomegalovirus strain genetically identical to the isolate detected in urine before transplantation. Cytomegalovirus isolates from different sites (buffy coat, lung, and urine) of the same patient were also identical, but cytomegalovirus isolates from different patients were never identical. Our results suggest that some cytomegalovirus infections after bone marrow transplantation may be caused by strains present before transplantation. The great structural and genetic variability of cytomegalovirus isolates must be considered in the development of effective diagnostic and immunoprophylactic measures for infection after marrow transplantation.

No abstract

Cytomegalovirus and varicella-zoster virus recovery from sucrose phosphate (0.2 M SP) and 70% sorbitol (sorbitol) was compared after storage at -70, 4, and 20 degrees C over time. Recovery from 0.2 M SP was uniformly better. More tissue culture infective doses and infectious foci were recovered in cell monolayers inoculated with 0.2 M SP virus stocks as compared with viruses stored in 70% sorbitol. Although both viruses were isolated from diluted fresh stocks (10(-1) through 10(-4], freezing diluted virus suspensions generally resulted in diminished recovery. Similar stabilizing effects on respiratory syncytial virus and herpes simplex virus type 1 infectivities were observed when stocks were preserved in 0.2 M SP, as compared with 70% sorbitol. Overall, 0.2 M SP was better than 70% sorbitol for stabilizing cytomegalovirus, varicella-zoster virus, respiratory syncytial virus, and herpes simplex virus type 1 infectivities under the conditions tested.