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Biomedical subjects

T C Merigan

Publications and source records attributed to T C Merigan.

At least 325 records · Page 18Linked to original sources
PubMed1973

Studies on the toxicity and antiviral activity of various polynucleotides.

Various polynucleotides were examined for antiviral activity and toxicity in mice. Although the antiviral potency of the various interferon inducers varied, there was a concomitant variation in toxicity. This was reflected by a fivefold range in therapeutic ratio for the various compounds. In addition, no polynucleotide proved to be a more potent interferon inducer than polyinosinic.polycytidylic acid [(poly rI).(poly rC)]. Our results suggest that there may be intrinsic limitations to the development of polynucleotide interferon inducers having improved therapeutic ratios.

Animals↗
PubMed1973

Structure and infectivity of picornaviral RNA encapsidated by cowpea chlorotic mottle virus protein.

Poliovirus and Mengo virus RNA were shown to associate efficiently with cowpea chlorotic mottle virus protein to form pseudovirions. The sedimentation coefficient for the pseudovirions was similar to that of poliovirus, and electron microscope observations showed the Mengo pseudovirions to be similar in size to Mengo virus. Such pseudovirions were infectious and were more resistant to ribonuclease than viral RNA; however, under our assay conditions, their infectivity was about equal to that of viral RNA.

Animals↗
PubMed1972

Selective increase in lymphocyte interferon response to vaccinia antigen after revaccination.

Viral antigen prepared by heat inactivation of vaccinia virus stimulated production of interferon in association with transformation of sensitized human lymphocytes in vitro. Involvement of a macrophage-lymphocyte interaction in production of interferon stimulated by viral antigen was found in which macrophage greatly augmented the amount of interferon produced by lymphocytes. Reimmunization with live vaccinia virus resulted in a selective increase in the ability of lymphocytes to produce interferon in the presence of viral antigen 4-7 weeks later without a corresponding increase in the degree of already significant lymphocyte transformation. There was no correlation between the extent of lymphocyte transformation and the amount of interferon produced. The augmented interferon response after reimmunization described in this study may be a significant component of the protective effect of immunization with vaccinia against disease occurring after exposure to small-pox.

Adult↗
PubMed1972

In vivo release of previously cleared interferon by cycloheximide.

The release of previously cleared interferon by cycloheximide was studied in the mouse. When cycloheximide was administered after either endogenous interferon stimulation or administration of exogenous interferon, the clearance of interferon from the blood stream was interrupted and a sharp rise in interferon titer occurred approximately 6 hr after cycloheximide administration followed by a rapid decline to low levels. This effect was observed with either interferon stimulated endogenously (by polyriboinosinic.polyribocytidylic acid), or homologous (mouse) or heterologous (rabbit) interferon administered exogenously. Serum protein concentrations also exhibited this rise and fall phenomenon after cycloheximide administration although the magnitude of the change in protein concentrations was less pronounced than that observed with interferon. Hematocrits, although elevated in mice receiving cycloheximide, did not exhibit this rise and fall phenomenon. Hence, cycloheximide administration leads to the release into the circulation of previously cleared interferon as well as other proteins.

Animals↗
PubMed1972

Interferon, antibody, and other host factors in herpes zoster.

The influence of several factors on the course of herpes zoster was studied in 151 patients. Dissemination of zoster was associated with the presence of a concurrent disease, especially Hodgkin's disease, and/or the use of immunosuppressive therapy. Several host-immune parameters, including quantitative immunoglobulins, circulating lymphocyte counts, delayed hypersensitivity to multiple skin test antigens, and lymphocyte transformation to phytohemagglutinin did not correlate with dissemination of disease. Development of virus-specific complement-fixing antibody (CFA) was delayed in some patients with disseminated disease. Vesicle interferon (V-IF) titers were low early in the disease in patients with localized and disseminated zoster and then rose, usually abruptly, to a peak value and declined as pustulation and crusting occurred. However, titers in patients with localized disease rose at an earlier time. This could be seen in terms of time to development of intermediate values of V-IF or by the day on which the sharpest rise occurred. In 15 carefully studied patients with disseminated disease, the development of the maximum V-IF response was followed within 48 hr by cessation of dissemination. Half of the patients in this group had no CFA detectable until after dissemination had ceased. These findings suggest at least two host factors whose interaction might determine host response to zoster; local interferon production (possibly mediated by sensitized lymphocytes) and humoral antibody, acting to prevent or shorten dissemination of an initially local disease.

Antibody Formation↗