Parallel investigations of the effects of adenosine on evoked potentials and cyclic AMP accumulation in hippocampus slices of the rat.

In slices of rat hippocampus, adenosine and its receptor agonist, 2-chloro-adenosine, were both found to (a) enhance the intracellular accumulation of cyclic adenosine monophosphate (cAMP) and (b) depress neuronal evoked responses to electrical stimulation. The differences in the dose/effect curves for the biochemical and electrophysiological changes cast doubt on a causal relationship between the two effects.     

The mechanism of stimulation of the antiviral factor (AVF) in Nicotiana leaves. The involvement of phosphorylation and the role of the N-gene.

Crude preparations of a precursor of the antiviral factor (pre-AVF) were made from noninfected Nicotiana leaves, either carrying the N-gene or from which the N-gene is absent. These pre-AVF preparations could be activated to give antiviral activity. Crude enzyme preparations, made only from N-gene-carrying plants, but regardless of TMV-infection, served as activating systems. This activation requires ATP, CAMP and cGMP and is associated with the appearance of a new phosphor ylated material seen by polyactylamide gel electrophoresis. The induced antiviral activity has been purified as AVF but was separated from the phosphorylated material. It is proposed that an activating system, determined by the N-gene, is itself being activated through phosphorylation following TMV infection and processes a “pre-AVF” to make active AVE.     

Does hyperimmunoglobulinemia-E protect tropical populations from allergic disease?

The Waorani Indians of eastern Ecuador have the highest blood concentration of IgE reported in a human population. Evidence obtained by medical history, physical examination, and immediate hypersensitivity skin tests suggests that pollen allergy and other atopic diseases are rare among the Waorani. A similar association between parasite-induced hyperimmunoglobulinemia-E and a low prevalence of conventional atopic disease has been reported in numerous other tropical populations. Saturation of mast cell IgE receptors with antibodies directed to the parasite and/or other antigens and competitive inhibition of passive binding of pollen allergen-specific IgE is one hypothetical cause of this association. We have tested this interesting conjecture by passively sensitizing the skin of Waorani Indians with serum containing pollen allergen-specific IgE antibodies. Waorani Indians with hyperimmunoglobulinemia-E can be adoptively sensitized with human ragweed or rye grass hyperimmune IgE antisera. This suggests that the cutaneous mast cells of healthy Waorani have active IgE receptors. The high circulating plasma concentrations of IgE in the Waorani do not prevent adoptive cutaneous sensitization with pollen-specific IgE antibodies.     

Distinguishing characteristics of a new neuroblastoma cell line

The characteristics of a new neuroblastoma cell line (MC-NB-1) established from the bone marrow of a 2-year-old male are described. Morphologically, the cells appear as flattened and epithelial-like or as small and spherical. Electron microscopy demonstrated microtubules and dense core secretory granules. The doubling time was approximately 35 hr. Isoenzyme patterns and catecholamine secretion indicated a human line of neuronal origin. The soft agar tumor colony forming system demonstrated drug resistance in vitro comparable to in vivo nonresponsiveness. The stemline karyotype of MC-NB-1 is 44,Y,del(1) (p22:), -4, -7, +del(7)(q22:), -16, +t(7;16)(16pter leads to 16q24::7q22 leads to 7q32), -17. Additionally, double-minute bodies were observed. However, no evidence of homogeneous staining regions (HSRs) were detected.     

Genome rearrangements of bovine rotavirus after serial passage at high multiplicity of infection

After serial passage at high multiplicity of infection of standard bovine rotavirus in MA104 cells, different genome rearrangements occurred in which segment 5 was lost from the RNA profile and distinct additional bands of double-stranded (ds) RNA were found in positions on gels between segments 1 and 6. It was shown that some of the additional RNA bands contained segment 5-specific sequences. The additional RNA bands were transcribed in vitro to apparent full length. Analysis of the proteins synthesized in cells infected with viruses possessing rearranged genomes showed that in all cases the product of RNA segment 5, VP5, was missing; however, in one case an abnormal protein was observed which corresponded in size to the coding capacity of the mRNA transcribed from the additional genomic RNA band. Viruses with rearranged genomes could be plaque purified, and they grew in the absence of standard virus to titers comparable to those obtained from standard virus. In mixed infections of standard virus and virus possessing genome rearrangements, standard virus overgrew during passage at low multiplicity of infection whereas virus possessing genome rearrangements overgrew during passage at high multiplicity of infection.     

Characterization of two abundant mRNAs of Autographa californica nuclear polyhedrosis virus present late in infection

Cytoplasmic poly(A)(+) RNA isolated from Spodoptera frugiperda cells late after infection with Autographa californica nuclear polyhedrosis virus (30-40 hr pi) was fractionated according to size on denaturing methyl mercury gels. Two major RNA species (1.4 kb and 0.75 kb) and several minor RNA species were detected by ethidium bromide staining. The predominant RNA species of about 1.4 kb was considered to be polyhedrin mRNA because (1) in vitro translation of the RNA, which was eluted from methyl mercury gels, yielded a polypeptide of MW 33K, which comigrated with polyhedrin. (2) When poly(A)+ RNA was fractionated on a sucrose column and then translated in vitro, the distribution and abundance profiles of a 33K polypeptide product and of 1.4-kb RNA were similar. (3) The 33K polypeptide made in vitro and purified polyhedrin gave rise to similar patterns of peptides when digested with S. aureus V8 protease. The polyhedrin mRNA (1.4 kb) hybridized to BamHI-F and HindIII-V AcNPV DNA fragments and hybridization selection with BamHI-F AcNPV DNA yielded a 33K polypeptide, which comigrated with polyhedrin. The second RNA species (0.75 kb in size) hybridized to overlapping EcoRI-P and HindIII-Q regions of the AcNPV genome and translated into a methionine deficient polypeptide of MW = 8K. It was synthesized in large quantities late in the infection and appeared to be coordinately expressed with polyhedrin in infected cells. The 8K polypeptide was detected as early as 15 hr pi and was still synthesized at 60 hr pi.     

Psychosis as a predictor of response to lithium maintenance treatment in bipolar affective disorder

Sixty-six bipolar I lithium clinic patients were studied for a history of psychotic symptoms at some time during the course of their illness. Agreement between different sources of information was calculated, and the patient population was divided into psychotic and non-psychotic subgroups. Probability of remaining well on lithium for the different subgroups was analyzed by the life table method. Psychosis during mania appeared to be associated with especially good early lithium prophylaxis.     

Inhibition of vaccinia virus late protein synthesis by isatin-beta-thiosemicarbazone: characterization and in vitro translation of viral mRNA.

Thespecific effect of istin-βthiosemicarbozone (IBT) was manifested after vaccinia virus late protein synthesis had commenced. At 6 hr after infection, viral protein synthesis was inhibited by about 9596. We confirmed that λ portion of the virus-specific RNA appears to be degraded (B. Woodson and W. K. Joklik, 1965, Proc. Nat. Acad. Sci. USA 54,946–953). Nevertheless, the amount of viral RNA that was capped, properly methylated, and polyadenylylated, was reduced by only about 50%. Moreover, RNA from IBT-treated cells stimulated cell-free protein synthesis to one-half the level obtained with RNA from control cells. Polyacrylamide gel electrophoretic analysis further demonstrated that RNA from IBT-treated cells was translated into late viral proteins in vitro. Thus, it seems possible that the inhibition of protein synthesis in IBT-treated cells does not result entirely or directly from either an inhibition of mRNA synthesis or from λ depletion of mRNA caused by accelerated degradation. An alternative possibility, that accelerated degradation is secondary to λ more immediate effect of the drug on protein synthesis, was considered.     

Cell division requirement for activation of murine leukemia virus in cell culture by irradiation.

Actively dividing cultures of AKR mouse cells were exposed to relatively low dose-rates of gamma radiation and tested for activation of endogenous leukemia viruses. Efficient and reproducible induction of virus was obtained with actively dividing cells, but cultures deprived of serum to inhibit cell division before and during gamma irradiation were not activated, even when medium with serum was added immediately after irradiation. These results show that cell division was required for virus induction but that a stable intermediate similar to the state induced by halogenated pyrimidines was not formed. In actively dividing AKR cell cultures, virus activation appeared to be proportional to the dose of gamma radiation; the estimated frequency of activation was 1.8 × 10^?5 per exposed cell and the efficiency of activation was approximately 0.012 inductions per cell per rad. Other normal primary and established mouse cell cultures tested were not activated by gamma radiation. The requirement of cell division for radiation and chemical activation may reflect some common mechanism for initiation of virus expression.