A viral subunit immunogen for porcine transmissible gastroenteritis.

An immunogenic component was isolated from both the Illinois (propagated in young swine) and the Miller (cell culture-adapted) strains of porcine transmissible gastroenteritis (TGE) virus. The viral subunit was released from the virion by sonication and was separated from intact virus and other viral components by isopycnic centrifugation. It had a buoyant density in sucrose of 1.02 g/ml. Further purification consisted of gel filtration through Sephadex G200, in which process the immunogen, with a molecular weight of approximately 25 000, was the last component to be eluted. A group of ten young, weaned swine, inoculated intramuscularly with two or three 1-mg doses of the viral subunit were protected against challenge with virulent TGE virus, probably by the induction of secretory IgA. The immunogen also induced a humoral immune response of variable magnitude (titers ranging from 8 to 5 625) in the animals. These antibodies are not believed to be directly related to protection against infection. They can, however, be easily identified by serologic procedures and may serve as a convenient indicator of responsiveness to the TGE viral immunogen.

Raptor responses to low-level jet aircraft and sonic booms.

We estimated effects of low-level military jet aircraft and mid- to high-altitude sonic booms (actual and simulated) on nesting peregrine falcons (Falco peregrinus) and seven other raptors by observing their responses to test stimuli, determining nesting success for the test year, and evaluating site reoccupancy rates for the year following the tests. Frequent and nearby jet aircraft passes: (1) sometimes noticeably alarmed birds, (2) occasionally caused birds to fly from perches or eyries, (3) most often evoked only minimal responses, and (4) were never associated with reproductive failure. Similarly, responses to real and simulated mid- to high-altitude sonic booms were often minimal and never appeared productivity limiting. Eighteen (95%) of 19 nest sites subjected to low-level jet flights and/or simulated sonic booms in 1980 fledged young during that year. Eighteen (95%) of 19 sites disturbed in 1980 were reoccupied by pairs or lone birds of the same species in 1981. We subjected four pairs of prairie falcons (Falco mexicanus) to low-level aircraft at ad libitum levels during the courtship and incubation phases when adults were most likely to abandon: all four eyries fledged young. From heart rate (HR) data taken via a telemetering egg at another prairie falcon eyrie, we determined that stimulus-induced HR alterations were comparable to rate changes for birds settling to incubate following flight. While encouraging, our findings cannot be taken as conclusive evidence that jet flights and/or sonic booms will have no long-term negative effects for other raptor species or for other areas. In addition, we did not experiment with totally naive wild adults, rotary-winged aircraft, or low-level sonic booms.

The domain model for eukaryotic DNA organization. 2: A molecular basis for constraints on development and evolution.

A model for eukaryotic DNA organization has been proposed in which DNA regulatory processes depend on multiple site-specific DNA-nuclear matrix interactions throughout a DNA domain. In this model gene regulation depends on combinations of a few control factors in a cell to activate cell type-specific genes. This model suggests simple molecular mechanisms for organismal development which can account for sequential activation of appropriate groups of genes throughout development and for specific constraints on developmental pathways. Additionally, these suggested developmental pathways are consistent with mechanisms of evolution in which gradualism and punctuated equilibrium are not exclusive of one another and are interrelated mechanisms of evolution that are both induced by specific chromosomal mutations.

Potentiation of the anti-inflammatory and analgesic activity of aspirin by caffeine in the rat.

Caffeine has been found to potentiate the acute anti-inflammatory activity of aspirin, indomethacin, and phenylbutazone, but not the activity of sodium salicylate or hydrocortisone, in the carrageenan pleurisy or hindlimb models of inflammation in the rat. The mobilization of inflammatory cells was not affected by aspirin in the presence or absence of caffeine. The mild analgesia produced by aspirin was confined to a hyperalgesic test in which this drug was able to reduce inflammation and concomitant hyperalgesia and thereby produce an "apparent" analgesic effect. This "apparent" analgesia produced by aspirin was potentiated by caffeine. The mechanism responsible for the potentiated anti-inflammatory and mild analgesic activity of aspirin remains unknown since caffeine did not alter the plasma salicylate levels or prostaglandin synthetase inhibition produced by aspirin.