Serum-neutralizing antibody to VP4 and VP7 proteins in infants following vaccination with WC3 bovine rotavirus.

Serum specimens from infants 2 to 12 months old vaccinated with the WC3 bovine rotavirus were analyzed to determine the relative concentrations of neutralizing antibody to the VP4 and VP7 proteins of the vaccine virus. To do this, reassortant rotaviruses that contained the WC3 genome segment for only one of these two neutralization proteins were made. The segment for the other neutralization protein in these reassortants was from heterotypic rotaviruses that were serotypically distinct from WC3. Sera were examined from 31 infants who had no evidence of a previous rotavirus infection and the highest postvaccination WC3-neutralizing antibody titers (i.e., 160 to 600) of the 103 subjects administered the vaccine. A reassortant (3/17) that contained both neutralization proteins from the heterotypic rotaviruses, i.e., EDIM (EW strain of mouse rotavirus) VP7 and rhesus rotavirus VP4, was not neutralized by these sera (geometric mean titer [GMT], less than 20). A reassortant (E19) that contained EDIM VP7 and WC3 VP4 was also very poorly neutralized by these antisera (GMT = 20). In contrast, antibody titers to a reassortant (R20) that contained WC3 VP7 and rhesus rotavirus VP4 were higher than those against WC3 (GMTs of 458 and 313, respectively). Thus, VP7 appeared to be the dominant immunogen for production of neutralizing antibody after intestinal infection of previously uninfected infants vaccinated with WC3 bovine rotavirus.     

Stochastic versus deterministic variability in simple neuronal circuits: II. Hippocampal slice.

Long time series of Schaffer collateral to CA1 pyramidal cell presynaptic volleys (stratum radiatum) and population spikes (stratum pyramidale) were evoked (driven) in rat hippocampal slices. From the driven CA1 region in normal [K+] perfusate, both population spike amplitude and an input-output function consisting of population spike amplitude divided by the presynaptic volley amplitude were analyzed. Raising [K+] in the perfusion medium to 8.5 mM, slices were induced to spontaneously burst fire in CA3 and long time series of inter-burst intervals were recorded. Three tests for determinism were applied to these series: a discrete adaptation of a local flow approach, a local dispersion approach, and nonlinear prediction. Surrogate data were generated to serve as mathematical and statistical controls. All of the population spike (6/6) and input-output (6/6) time series from the normal [K+] driven circuitry were stochastic by all three methods. Although most of the time series (5/6) from the autonomously bursting high [K+] state failed to demonstrate evidence of determinism, one (1/6) of these time series did demonstrate significant determinism. This single instance of predictability could not be accounted for by the linear correlation in these data.     

Effects of modeling and lineage on fishing behavior in the small-eared bushbaby (otolemur garnettii)

Thirty-eight bushbabies(Otolemur garnettii)were subjects in an observational learning study. We exposed them to one of three modeling conditions: (1) fishing model—one that actually performed fishing behavior; (2) nonfishing model—one that performed as a model in every way except performance of fishing behavior; and (3) no model. We assessed them with regard to latency to approach the fishbowl, latency to make an initial fishing attempt, duration of time spent in the vicinity of the fishbowls, and number of actual fishing attempts. Results indicate that subjects that were exposed to either fishing or nonfishing models were faster to approach the fishbowls and spent more time in the vicinity of the fishbowls than animals in the no-model condition Lineage, i.e., whether or not the animals’ parents fished, rather than modeling condition, was the best predictor of the latency to initial fishing attempt and the number of attempts made.     

Comparative sequence analysis of the reovirus S4 genes from 13 serotype 1 and serotype 3 field isolates.

The reovirus sigma 3 protein is a major outer capsid protein that may function to regulate translation within infected cells. To facilitate the understanding of sigma 3 structure and functions and the evolution of mammalian reoviruses, we sequenced cDNA copies of the S4 genes from 10 serotype 3 and 3 serotype 1 reovirus field isolates and compared these sequences with sequences of prototypic strains of the three reovirus serotypes. We found that the sigma 3 proteins are highly conserved: the two longest conserved regions contain motifs proposed to function in binding zinc and double-stranded RNA. We used the 16 viral isolates to investigate the hypothesis that structural interactions between sigma 3 and the cell attachment protein, sigma 1, constrain their evolution and to identify a determinant within sigma 3 that is in close proximity to the sigma 1 hemagglutination site.     

Nonlinear autoregressive analysis of the 3/s ictal electroencephalogram: implications for underlying dynamics

 In a previous study, nonlinear autoregressive (NLAR) models applied to ictal electroencephalogram (EEG) recordings in six patients revealed nonlinear signal interactions that correlated with seizure type and clinical diagnosis. Here we interpret these models from a theoretical viewpoint. Extended models with multiple nonlinear terms are employed to demonstrate the independence of nonlinear dynamical interactions identified in the ‘NLAR fingerprint’ of patients with 3/s seizure discharges. Analysis of the role of periodicity in the EEG signal reveals that the fingerprints reflect the dynamics not only of the periodic discharge itself, but also of the fluctuations of each cycle about an average waveform. A stability analysis is used to make qualitative inferences concerning the network properties of the ictal generators. Finally, the NLAR fingerprint is analyzed in the context of Volterra-Weiner theory. Received: 6 April 1994/Accepted in revised form: 18 November 1994     

Renovascular Hypertension: Pathophysiology,Diagnosis, and Treatment

Renovascular hypertension can result from renal artery lesions involving the main renal artery, or its branches. It is generally felt that the elevation of blood pressure results from excessive systemic vasoconstriction secondary to enhanced renin secretion by one or part of one kidney. Renin secretion is enhanced because of constriction of the renal artery and resultant intrarenal ischemia. Clinically patients cannot be distinguished from those with essential hypertension and diagnosis must be made with arteriography although urography and isotope renography may suggest the diagnosis. Surgical cure can be predicted if differential renal vein renin ratios lateralize but a non-lateralizing study does not necessarily mean that surgery will fail. In properly selected patients, surgical results are excellent.     

Events Surrounding the Early Development of Euglena Chloroplasts: 7. Inhibition of Carotenoid Biosynthesis by the Herbicide SAN 9789 (4-Chloro-5-(methylamino)-2-(alpha,alpha,alpha,-trifluoro-m-tolyl)-3-(2H)pyridazinone) and Its Developmental Consequences

The herbicide SAN 9789 (4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl-3- (2H)pyridazinone) blocks carotenoid synthesis in growing and resting cells of Euglena at concentrations of 20 to 100 μg/ml without affecting cell viability. Although the inhibition is immediate and complete, in resting cells no decrease in already synthesized carotenoids is found indicating a lack of turnover. In cells growing in the dark, carotenoids are diluted out as the cells divide. Cells dividing in the light in the presence of SAN 9789, eventually lose viability, presumably because of photooxidations usually prevented by carotenoids. During 72 hours of light-induced plastid development in dark-grown resting cells, none of the usual carotenoids increase while phytoene accumulates, indicating that SAN 9789 blocks carotenoid synthesis at this point. Chlorophyll synthesis and membrane formation are also blocked by the herbicide, but these inhibitions appear to be secondary to the inhibition of carotenoid synthesis. That carotenoid levels are strongly correlated with and may control the synthesis of chlorophyll and the formation of plastid membranes is suggested by the following data. (a) If dark-grown dividing cells are placed in the presence of the herbicide for various periods, rested and exposed to light in the presence of the drug, different amounts of carotenoids remain in the cells and the amount of chlorophyll finally synthesized is proportional to the amount of carotenoids present. (b) Photodestruction of chlorophyll is excluded, since the same amounts of chlorophyll are formed at intensities of 10 to 100 foot-candles of light. (c) Photoconversion of protochlorophyll(ide) to chlorophyll(ide) in dark-grown cells is not blocked by the herbicide. (d) Initial rates of chlorophyll synthesis are the same in treated and nontreated cells. (e) The extent of membrane formation appears to parallel the amount of carotenoids present as judged by electron microscopy.     

Murine virus susceptibility of cell cultures of mouse, rat, hamster, monkey, and human origin.

Studies were initiated to determine the practicality of using various tissue cultures for the propagation of murine viruses isolated from laboratory animals. The cytopathogenic effects of 10 murine viruses known to cause disease in laboratory rodents were compared in monolayer cultures of L929, BHK-21, WI-38, BSC-1, and Vero cells. The susceptibility of primary hamster embryo, hamster kidney, mouse embryo, mouse kidney, and rat embryo cell cultures was also tested. Seven of the viruses produced effects in at least 1 of the cell substrates. The remaining 3 viruses, namely H-1, K, and mouse hepatitis, produced no effects in the cell cultures tested.