Immunopotentiation of a Developed Salmonella enterica serotype Enteritidis Vaccine by Thymulin and Zinc in Meat Chicken Breeders

The humoral immunity, spleen and thymus weight indices, lymphocyte count in the thymus cortex, and granuloma diameter at vaccination sites were assessed in four differently immunopotentiated groups of meat chicken breeders. Breeders in the first two groups were given a killed Salmonella enterica serotype Enteritidis (SE) vaccine subcutaneously at 15 and 19 weeks of age. Breeders in the third and fourth groups were left unvaccinated. Breeders in the first group were further immunopotentiated with zinc and thymulin. Each bird in the first group was given the immunopotentiators intraperitoneally in a volume of 0.1 ml at intervals of 3 days for a period of 3 weeks, starting at 15 weeks of age. At each time, each bird in the first group received thymulin (10 ng) and ZnCl₂ (1 mol/L), using a carboxymethyl cellulose carrier, totalling 90 ng thymulin and 9 mol of ZnCl₂ per bird. Each bird in the first three groups was challenged orally with 6.7×10⁶ cfu/ml of highly virulent SE organisms, at an age of 22 weeks. The first group, which had received zinc and thymulin, had the earliest and highest humoral immune response to SE (p<0.05). This was observed at 2 and 4 weeks after the first vaccination. In addition, the first group had the highest mean thymus weight index, and the highest mean lymphocyte count in the thymus cortex. No significant difference was observed between the first two vaccinated groups in the mean granuloma diameter developed at the two vaccination sites 48 h after administration of the vaccine (p>0.05).     

Storage of methane and freon by interstitial van der Waals confinement

A known host-guest assembly, organized only by means of relatively weak dispersive forces, exhibits hitherto unappreciated thermal stability. The hexagonal close-packed arrangement of calix[4]arene contains lattice voids that can occlude small, highly volatile molecules. This host-guest system can be exploited to retain a range of freons, as well as methane, not only well above their normal boiling points, but also at relatively high temperatures and low pressures. The usually overlooked van der Waals interactions in organic crystals can indeed be used in a highly stable supramolecular system for gas storage.     

A single recombinant plasmid expressing two major outer surface proteins of the Lyme disease spirochete

A gene bank of DNA from the Lyme disease spirochete was constructed in the plasmid pBR322. Plasmid pTRH32, a recombinant that in Escherichia coli expresses the two major outer surface proteins of the Lyme disease spirochete, was identified. One of the recombinant products, designated OspA, represents a surface protein that appears to be common to all Lyme disease spirochetes, whereas the other recombinant product, designated OspB, represents a more variable surface protein. This recombinant plasmid provides a foundation for future studies on the epidemiology and pathogenesis of Lyme disease as well as on the genetic organization of the etiologic agent.