Rapid profiling of bacterial quinones by two-dimensional thin-layer chromatography

Bacterial quinones were analysed by two-dimensional thin-layer chromatography with ready-made, multi-phase silica gel plates which allowed good separation of complicated quinone mixtures. A combination of this method and silver-ion-modified thin-layer chromatography made it possible to identify partially hydrogenated quinones.     

Reversible inhibition of osteoclastic activity by bone-bound gallium (III).

Gallium(III) is a new therapeutic agent for hypercalcemia. Ga3+ reduces osteoclast action, but how it inhibits the cell's physiology is unknown. In vivo, 7-12 microM Ga(III) reduces calcium release from bone, but surprisingly, 10-100 microM Ga3+ added to isolated avian osteoclasts did not reduce their degradation of L-(5-3H)-proline bone. 3H-proline labels bone collagen specifically, and collagenolysis is an excellent indicator of bone dissolution because collagen is the least soluble component of bone. Ga(III) greater than 100 microM inhibited osteoclasts in vitro, but also killed the cells. To resolve this apparent conflict, we measured 67Ga distribution between bone, cells, and media. Gallium binds avidly but slowly to bone fragments. One hundred micrograms of bone clears 60% of 1 microM gallium from 500 microliters of tissue culture medium, with steady state at greater than 24 h. Osteoclasts on bone inhibited gallium binding capacity approximately 40%, indicating a difference in available binding area and suggesting that osteoclasts protect their substrate from Ga binding. Less gallium binds to bone in serum-containing medium than in phosphate-buffered saline; 30% reduction of the affinity constant suggests that the serum containing medium competes with bone binding. Consequently, the effect of [Ga] on bone degradation was studied using accurately controlled amounts of Ga(III) pre-bound to the bone. Under these conditions, gallium sensitivity of osteoclasts is striking. At 2 days, 100 micrograms of bone pre-incubated with 1 ml of 1 microM Ga3+, with 10 pmoles Ga3+/micrograms bone, was degraded at 50% the rate of control bone; over 50 pM Ga3+/micrograms bone, resorption was essentially zero. In contrast, pre-treatment of bone with [Ga3+] as high as 15 microM had no significant effect on bone resorption rate beyond 3 days, indicating that gallium below approximately 150 pg/micrograms bone acts for a limited time and does not permanently damage the cells. We conclude that bone-bound Ga(III) from medium concentrations less than 15 microM inhibits osteoclasts reversibly, while irreversible toxicity occurs at solution [Ga3+] greater than 50 microM.     

Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae)

We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation.     

Serum IgE levels in rats infected with Paragonimus westermani]

Paragonimus westermani is a common fluke in Korea. The present study aimed to determine serum total IgE and specific IgG levels in experimental paragonimiasis of rats. Each Wistar rat was inoculated orally with 20-25 metacercariae of P. westermani from Cambaroides similis. Before and after infection (1, 2, 3, 4, 6, 8 weeks) of P. westermani, the blood was collected from the retro-orbital venous plexus of rats and kept serum at -70 degrees C. Serum total IgE and specific IgG levels were determined by the capture and conventional enzyme-linked immunosorbent assay, respectively. The results were as follows; 1. Serum IgE values were increased to 0.18 +/- 0.042 at 2 weeks, 0.28 +/- 0.151 at 4 weeks and 0.43 +/- 0.055 at 8 weeks after infection. The absorbances of non-infected rats ranged 0.07 +/- 0.021-0.12 +/- 0.025. 2. Specific IgG values were slightly increased at 3 weeks (0.20 +/- 0.032) and gradually increased up to 8 weeks (0.31 +/- 0.067) after infection. The absorbances of non-infected rats ranged 0.11 +/- 0.035-0.18 +/- 0.019. The present results suggested that P. westermani could elevate serum IgE and specific IgG antibodies in Wistar rats which were not a good definitive host.     

Correlation between cell wall extensibility and the content of diferulic and ferulic acids in cell walls of Oryza sativa coleoptiles grown under water and in air

Rice ( Oryza sativa L. cv. Sasanishiki) coleoptiles grown under water achieved greater length than those grown either in air or under water with constant air bubbling. The extensibility of cell walls in coleoptiles grown under water was larger than that in the other treatments. Per unit length of the coleoptile, the content of ferulic and diferulic acids ester-linked to hemicelluloses was higher in air and bubbling type coleoptiles than in water type ones. The extensibility of the coleoptile cell walls correlated with the content of diferulic acids per unit length and per hemicellulose, suggesting that the enhancement of the formation of diferulic acid bridges in hemicelluloses in air or under water with air bubbling makes the cell walls mechanically rigid; thereby inhibiting cell elongation in rice coleoptiles. In addition, the ratio of diferulic acid to ferulic acid was almost constant irrespective of coleoptile age, zone and growth conditions, suggesting that the feruloylation of hemicelluloses is rate-limiting in the formation of diferulic acid bridges in the cell walls of rice coleoptiles.