Showing papers by "Thomas C. Merigan published in 1966"
198 citations
TL;DR: Experiments are reported which establish the inhibition of a TRIC agent by virus-induced mouse interferon in L cells, which appears that TRIC agents are more closely related to obligate intracellular bacteria or rickettsiae than to true viruses.
Abstract: The causative agents of trachoma and inclusion conjunctivitis (TRIC) have been called viruses in the past. However, TRIC agents possess several characteristics which clearly separate them from typical viruses. They possess a bacteria-like cell wall containing muramic acid; they contain both DNA and RNA; they elaborate enzymes involved in decarboxylation of carbohydrates and in folic acid synthesis; they are inhibited by antibacterial drugs; and at least some stages in the development of TRIC agents involve binary fission(l). Thus it appears that TRIC agents are more closely related to obligate intracellular bacteria or rickettsiae than to true viruses.Up to the present time, interferons have been known to act only on true viruses. It was, therefore, of interest to determine whether virus-induced interferons would inhibit the replication of the more complex TRIC agents. Early in this work we were made aware of a publication by Mordhorst and Reinecke(2) in which it was claimed that interferon had no effect ...
94 citations
TL;DR: The electrophoretic behavior of this material on polyacrylamide gel indicated that it, like chick and mouse interferons, has an isoelectric point near neutrality.
77 citations
TL;DR: Carl Strauss1 was able to collect 18 cases from the literature and his personal files, and he presented a report on cystic disease of the renal medulla which presented a new perspective on the disease.
Abstract: CYSTIC disease of the renal medulla is an infrequently recognized disease of the human kidney. Strauss1 was able to collect 18 cases from the literature and his personal files, and he presented a r...
76 citations
TL;DR: Characterization of this material has shown it to fulfill many of the criteria used to define interferon, and inoculation of an avirulent strain of T. gondii resulted in protection against later challenge by a virulent neurotropic virus.
Abstract: SummaryToxoplasma gondii has been shown to induce in vivo an antiviral substance whose action is demonstrable both in tissue culture and in vivo. Characterization of this material has shown it to f...
57 citations
TL;DR: A TRIG agent (LB-1), a member of the psittacosis-LGV-trachoma group, can induce the production in vivo and in vitro of a material with antiviral activity similar to virus-induced interferon.
Abstract: SummaryA TRIG agent (LB-1), a member of the psittacosis-LGV-trachoma group, can induce the production in vivo and in vitro of a material with antiviral activity similar to virus-induced interferon. The interferon induced in cell culture by LB-1 had a molecular weight of about 50,000 and hence appeared to differ significantly from virus-induced interferon prepared in cell culture or in vivo.Addendum: The peak of TRIC-induced interferon production in serum of mice is late (6-13 hours), similar to that of virus(3), brucella(3), or statalon(lO), but distinct from the early (2 hour) peak appearing after endotoxin(4).
35 citations
TL;DR: It is demonstrated that, in the mouse, the molecular weight of EII is greater than that of VII, and the molecular sizes of rabbit serum interferons induced by virus and by endotoxin are studied.
Abstract: THERE is evidence that, in the rabbit, virus-induced interferon (VII) is induced differently from endotoxin-induced interferon (EII). The induction of VII is inhibited by actinomycin D (ref. 1) and by puromycin2, while the induction of EII is not. Furthermore, Hallum et al.3 demonstrated that, in the mouse, the molecular weight of EII is greater than that of VII. In view of these differences between EII and VII, we decided to study the molecular sizes of rabbit serum interferons induced by virus and by endotoxin.
30 citations
TL;DR: The effect of purified chicken interferon on growth of uninfected chick cells in tissue culture was studied and the criteria for growth used were the increase in amounts of protein, DNA and RNA, and the synthetic rates of protein and RNA.
Abstract: ConclusionsThe effect of purified chicken interferon on growth of uninfected chick cells in tissue culture was studied. The criteria for growth used were the increase in amounts of protein, DNA and RNA, and the synthetic rates of protein and RNA. Doses of interferon that were strongly inhibitory to viral growth caused no changes in these parameters.
29 citations
TL;DR: The antiviral activity of crude interferon preparations was not always correlated with inhibition of cell growth suggesting the presence of a noninterferon growth inhibitor in many preparations of interferons.
Abstract: SummaryThe antiviral activity of crude interferon preparations was not always correlated with inhibition of cell growth suggesting the presence of a noninterferon growth inhibitor in many preparations of interferon. This interpretation is consistent with the further observations that: 1) growth inhibition was not increased as was the antiviral action of interferon in a second preparation of crude mouse interferon, and 2) purified chicken interferons did not inhibit cell growth.
25 citations
13 citations
TL;DR: Investigation of extracts of spleens from mice injected with statolon finds that, whereas the heavier interferon species isproduced in the serum, the lighter variety is produced in the spleen of such mice.
Abstract: WE have described two molecular species of interferon induced by statolon1. Both are proteins and one (produced in tissue culture) has a molecular weight of 30,000 with an electrophoretic mobility similar to that of virus induced interferon, whereas the other (produced in vivo) has a molecular weight of 85,000 and an electrophoretic mobility which differs significantly from that of virus induced interferon. In the present communication we report that the lighter of these species can also be produced in vivo by statolon. W. Van Rossum and P. de Somer have found the spleen to be a very active interferon producing organ (personal communication). We have-investigated extracts of spleens from mice injected with statolon and find that, whereas the heavier interferon species is produced in the serum, the lighter variety is produced in the spleen of such mice.