Laboratory assays of different types of field trial typhoid vaccines and relationship to efficacy in man

Pittman, Margaret (National Institutes of Health, Bethesda, Md.), and Howard J. Bohner. Laboratory assays of different types of field trial typhoid vaccines and relationship to efficacy in man. J. Bacteriol. 91:1713-1723. 1966.-Antibody responses of rabbits to H, O, and Vi antigens did not differentiate vaccine K (acetone-killed and dried) from vaccine L (heat-phenolized and dried) relative to human efficacy. A mouse protection assay in which intraperitoneal vaccination and challenge suspended in mucin were used showed vaccine K to be 3.69 times more potent than vaccine L; with subcutaneous vaccination, vaccine K was only 0.78 as potent. With the challenge suspended in saline, the effect of the route of vaccination was accentuated. An old U.S. reference vaccine, heat-phenolized, induced the same types of response as vaccine L. In the assay with intraperitoneal vaccination and mucin-suspended challenge, the potency of vaccine K relative to vaccine L and the potencies of Polish vaccines, P, N, and T, relative to vaccine K were directly correlated with the efficacies of the vaccines for man, as reported for the recent World Health Organization cooperative field trials in British Guiana, Yugoslavia, and Poland. This assay gave a high potency for alcohol-treated vaccine V relative to vaccine L, but the values did not reflect relative efficacy in the USSR field trial; the subcutaneous vaccination assay more closely reflected their human efficacy. An analysis suggested that vaccine K had a mouse protective factor not present in vaccine L and that vaccine V may have had a third factor. The influence of a few variable factors on the assay with intraperitoneal vaccination and mucin-suspended challenge was studied briefly.     

Acidity versus habitat structure as regulators of littoral microcrustacean assemblages

1. Emergence traps were set overnight on the sediment surface to sample the littoral microcrustaceans of 22 Canadian Shield lakes that ranged in pH from 4.56 to 6.92. Traps were randomly allocated in quintuplicate in both wave‐washed sandy habitats where pipewort (Eriocaulon septangulare) was the dominant macrophyte (termed pipewort habitats), and more protected habitats dominated by floating‐leaved macrophytes (termed floating‐leaved habitats). 2. In total, 50 cladoceran and 22 copepod species were found, with 16–45 species in each lake. Lakes that had never acidified exhibited a more diverse fauna than lakes that had acidified. 3. There were only minor differences between the numbers of species found in floating‐leaved versus pipewort habitats except for one lake. Non‐chydorid cladoceran, chydorids and copepods constituted 45%, 26% and 29% of the total number of individuals, respectively. 4. Based on presence/absence, dominance scores and frequency of occurrences of species, the microcrustacean faunal composition was similar in the two habitats. A detrended correspondence analysis confirmed that there was no separation between the two main types of habitat, and that pH was the parameter most strongly correlated with the dominant microcrustacean compositional gradient among lakes.     

Photochromic Pigments from Blue-Green Algae: Phycochromes a, b, and c

Aqueous extracts of blue-green algae were fractionated by electrofocusing. In all algae investigated, fractions with iso-electric points at or near 4.6 showed photochromic behaviour analogous to that of phytochrome, although they were sensitive to light of shorter wavelength. Three main types of photochromic pigments were found: Phycochrome a (in Tolypothrix distorta, Phormidium luridum, Nostoc muscorum 1453/12, and Anacystis nidulans) has one form absorbing maximally at about 590 nm (formed under red light) and one absorbing maximally at about 630 nm (formed under green light). Phycochrome b (in Tolypothrix distorta) has one form absorbing maximally near 510 nm and one form absorbing maximally at 570 nm (formed in yellow-green and blue-green light, respectively). Phycochrome c (in Nostoc muscorum A and probably in Tolypothrix tenuis) has one form absorbing maximally at 650 nm (formed under green light) and one absorbing very weakly in the green region (formed under red light). The conversion of Phormidium phycochrome a from its red-absorbing form to its green-absorbing form causes the same spectral change as if an f-chromophore of phycocyanin were transformed into an s-chromophore. The quantum yield for this conversion is estimated to be 0.1, while the quantum yield for the reversion is estimated to be 0.4 on the assumption that the absorption coefficients are those of f- and s-chromophores. Phycochrome c is less light-sensitive than phycochromes a and b.     

If You Knew What Was Good For You! The Value of Environmental Enrichments With Known Welfare Benefits Is Not Demonstrated by Sows Using Operant Techniques

This study assessed the motivation of gestating sows housed in standard, barren gestation stalls (used for breeding/implantation and/or gestation) for access to environmental enrichment. Enrichment consisted of a cotton rope or rubber mat in comparison to positive (additional food when fed at commercial levels) and negative (empty trough) controls. Although environmental enrichment may improve animal welfare, sows' valuation of enrichments is largely unknown. This study used an operant panel and obtained behavioral measures to quantify motivation. As indicated by a higher price paid and lower latencies to press the panel and enter the treatment stall (all comparisons, p < .05), sows demonstrated higher motivation for food compared with all treatments. Sows housed in gestation stalls did not demonstrate high motivation via operant responding for a cotton rope or a rubber mat; nor did they demonstrate any differences in behavioral measures (all comparisons, p > .10). Although sows' motivation for a mat did not differ from that for an empty trough, previous work has demonstrated the welfare benefits associated with comfort flooring.     

Light-Induced Absorption Changes in Etiolated Coleoptiles

Blue (or green) light induced reversible and irreversible absorption changes in etiolated wheat (Triticum aestivum) coleoptiles. Immediately after a 10 s pulse of blue light there was an absorbance increase at 440 nm and a decrease at 420 nm. The absorbance at 440 nm returned to the original level in a biphasic way, with first-order rate constants of 0.05 s^?1 and 0.006 s^?1 at 25°C. The change at 440 nm was partly, but not completely, inhibited by iodide. In the 500–600 nm region complex changes occurred, indicating the participation of at least two different cytochromes, one of which was oxidized during a 10 s light pulse and the other oxidized more slowly during the following dark period.     

Codes and abbreviations for approved of effectively published names of genera of bacteria published from January 1980 to December 1990.

Lists of abbreviations for genus names of bacteria are expanded to accommodate 103 new entries which are names that have been validity published since the publication of an updated list by Rogosa et al. in 1986 (Int. J. Syst. Bacteriol. 36:464-472). These abbreviations are provided to serve the need for appropriate codified abbreviations for use in processing or indexing of information on computers.