Showing papers on "Viremia published in 1972"
TL;DR: Virus titers in normal thymus were relatively low, but increased significantly with the development of thymic lymphoma, and the level of viremia decreased after the 1st month of life, but increase sharply in lymphomatous mice.
Abstract: Quantitative studies were made of the organ distribution of murine leukemia virus in AKR mice of various ages. Infectious virus first appeared shortly before or after birth and was continuously present in all mice thereafter. Highest infectivity titers were found in uterus and bone, with spleen slightly lower. Virus titers in normal thymus were relatively low, but increased significantly with the development of thymic lymphoma. The level of viremia decreased after the 1st month of life, but increased sharply in lymphomatous mice.
221 citations
TL;DR: It was concluded that white-tailed deer could be natural hosts for JC virus, and may serve as useful indicators for JC and LAC virus activity in nature.
Abstract: Prototype strains of four California group arboviruses were subcutaneously inoculated into 26 white-tailed deer (Odocoileus virginianus). Subsequent viremia and antibody data were the criteria used to evaluate deer as natural hosts and/or indicators for La Crosse (LAC), Trivittatus (TVT), snowshoe hare (SSH), and Jamestown Canyon (JC) viruses. Viremia was detected in 7 of 11 deer inoculated with LAC virus, 1 of 3 with TVT virus, 0 of 3 with SSH virus, and 8 of 9 with JC virus. Viremia with LAC and TVT viruses were of low titer and short duration (1 day), while JC virus viremia persisted for 4 to 5 days, with a peak titer of 3.4 Log10 SMICLD50/0.02 ml. Detectable tissue culture neutralization (TCN) antibodies to the homologous virus persisted for at least 90 days in 9 of 10 surviving deer inoculated with LAC virus, 1 of 3 with TVT virus, 0 of 3 with SSH virus, and 8 of 8 with JC virus. The sera reacted in highest titers to the homologous viruses, and highest titered cross-reactions were noted following LAC virus inoculation. It was concluded that white-tailed deer could be natural hosts for JC virus, and may serve as useful indicators for JC and LAC virus activity in nature.
22 citations
TL;DR: It was concluded that goats, being less expensive than cattle to purchase and house, could be suitable experimental subjects for studies of the epizootiology of FMD under laboratory conditions.
Abstract: Observations were made on the appearance and spread of foot-and-mouth disease (FMD) in groups of sheep and goats after either intranasal inoculation of virus or contact with an infected steer. Viremia was used as the primary indicator of the spread of infection. Of 91 goats exposed to virus, 88 (97%) became infected and 92% of the infected ones had demonstrable viremia. Comparable figures for sheep were 33 of 43 (77%) infected and 72% of these with viremia. It was concluded that goats, being less expensive than cattle to purchase and house, could be suitable experimental subjects for studies of the epizootiology of FMD under laboratory conditions.
19 citations
TL;DR: The data show that EAV can replicate effectively in the absence of significant host DNA synthesis, a point recently in dispute.
13 citations
TL;DR: In this paper, the authors used challenge response as the index of protection and found that the early protection phenomenon is one of interference, since little or no replication of a challenge virus occurred when it was administered during the vaccine viremia stage.
Abstract: The rapid onset and persistence of homologous and heterologous protection induced by attenuated Venezuelan equine encephalomyelitis (VEE) vaccine (TC-83) were studied in the hamster, by using challenge response as the index of protection. At 8 hr postvaccination with 103 median immunizing doses of TC-83 vaccine, 15 to 20% of animals were protected against challenge with VEE virus as well as Eastern and Western equine encephalomyelitis viruses. The percentage of protection increased with time postvaccination until 80 to 90% homologous and heterologous protection was achieved by 18 hr postvaccination. Temporal studies indicated that early protection (days 1 to 6) correlated with vaccine viremia, and that the percentage of protection against heterologous challenge decreased with the cessation of viremia. Data are presented to indicate that the early protection phenomenon is one of interference, since little or no replication of a challenge virus occurred when it was administered during the vaccine viremia stage.
9 citations
TL;DR: It is suggested that maintenance of optimal nutrition during acute infection may be important in sustaining the early anabolic response of the host and can prevent the decreased rate of growth.
Abstract: Mice, 14-16 days old, were challenged with coxsackie B3 virus to define and ascertain possible mechanisms for changes in amino acids in blood accompanying infection with this virus and to correlate amino-acid responses with viral titers in blood and myocardium and with gross and histopathologic evidence of disease. There was significant depression of total concentration of amino acids in blood and profound depression of amino acids important for protein synthesis 15 min after challenge; these changes persisted through day 5. Viremia was detectable from 15 min to day 6 after challenge. Myocardial virus persisted until day 10. Weights of infected animals were depressed on days 5 through 12, but compensatory growth was noted subsequently. Gross myocardial lesions were present in 50% of mice three months after challenge. These findings suggest that maintenance of optimal nutrition during acute infection may be important in sustaining the early anabolic response of the host and can prevent the decreased rate of growth.
8 citations
TL;DR: Hemagglutination-inhibiting (HI) antibodies were first detected 7 days following the "low-dose" inoculation and attained maximum titers of 160.0 at 60 days in animals receiving 10 mouse LD50 of Powassan virus but neutralizing antibodies, which did not appear until 30 days post inoculation, were present at a log neutralizing index (NI) of 2.0.
Abstract: Hamsters injected subcutaneously with a single "low-dose" inoculum (10 mouse LD50) of Powassan virus developed viremia titering 106.2 mouse LD50 per milliliter of blood whereas hamsters receiving a...
8 citations
23 Jun 1972
TL;DR: Data are presented to indicate that the early protection phenomenon is one of interference, since little or no replication of a challenge virus occurred when it was administered during the vaccine viremia stage.
Abstract: : The rapid onset and persistence of homologous and heterologous protection induced by attenuated Venezuelan equine encephalomyelitis (VEE) vaccine (TC-83) were studied in the hamster, by using challenge response as the index of protection. At 8 hr postvaccination with 1,000 median immunizing doses of TC-83 vaccine, 15 to 20% of animals were protected against challenge with VEE virus as well as Eastern and Western equine encephalomyelitis viruses. The percentage of protection increased with time postvaccination until 80 to 90% homologous and heterologous protection was achieved by 18 hr postvaccination. Temporal studies indicated that early protection (days 1 to 6) correlated with vaccine viremia, and that the percentage of protection against heterologous challenge decreased with the cessation of viremia. Data are presented to indicate that the early protection phenomenon is one of interference, since little or no replication of a challenge virus occurred when it was administered during the vaccine viremia stage.
1 citations