Antimitotics induced cardiolipin cluster formation possible role in mitochondrial enzyme inactivation

We demonstrate here that drugs which inactivate cytochrome c oxidase are able to segregate cardiolipin essential for the enzyme activity, in a separate phase inaccessible for the enzyme. A molecular explanation of the drug-induced aggregation process is proposed.     

Host plant pollen influences calling behavior and ovarian development of the sunflower moth,Homoeosoma electellum

Summary Females of the sunflower moth, Homoeosoma electellum held in the presence of pollen, or an ethanolic pollen extract, from the sunflower Helianthus annuus initiated calling behavior at a significantly younger age following emergence than those provided sucrose only. Furthermore, females with pollen subsequently spent more time calling, and had an increased rate of egg maturation, than those held without pollen. These effects were attributed to a kairomone as females held in the presence of, but denied direct access to, pollen behaved in the same manner as those in contact with pollen. The importance of this life history strategy for the exploitation of temporarily available resources, essential to the survival of neonate larvae, and on the dispersal of adults, is discussed.     

Structure of the adriamycin-cardiolipin complex. Role in mitochondrial toxicity

Adriamycin and its derivatives are among the most efficient antimitotics used in clinical therapy. A specific cardiotoxicity places a limit on the total dose of adriamycin that may be administered. The mechanism of cardiac toxicity is complex. Data accumulated from in vitro and in vivo studies indicate a possible common cause for the inhibition of numerous enzymes and tissue degradation by a free radical mechanism: the binding of adriamycin to the inner mitochondrial membrane cardiolipin. The structure of the adriamycin-cardiolipin complex has been investigated by using physico-chemical techniques and via conformational analysis. The results open a rational way to design new structures that are less cardiotoxic.     

Total biodegradation of 4-chlorobiphenyl (4 CB) by a two-membered bacterial culture

Summary Several bacterial strains that can oxidize mono- and dichlorinated biphenyls with one unsubstituted ring have already been described. The major route for this biodegradation leads ultimately to the corresponding chlorobenzoic acid, but several other minor chlorinated metabolites that might possibly be of concern for the environment have also been described previously. Since none of the bacterial strains that are able to oxidize these chlorinated biphenyls in pure culture are known to degrade chlorobenzoic acid, the oxidation of these substrates by axenic cultures always generates chlorobenzoates plus several other metabolites. In the present study, we have estimated the biodegradation of 4-chlorobiphenyl (4CB) by a two-membered bacterial culture containing one strain able to grow on 4CB and to transform it into 4-chlorobenzoate (4CBA) and one strain able to degrade 4CBA. The results were encouraging, since it was shown that the degradation of 4CB was more rapid and complete with the double bacterial culture.     

Scale-up of the adenovirus expression system for the production of recombinant protein in human 293S cells

Human 293S cells, a cell line adapted to suspension culture, were grown to 5×10⁶ cells/mL in batch with calcium-free DMEM. These cells, infected with new constructions of adenovirus vectors, yielded as much as 10 to 20% recombinant protein with respect to the total cellular protein content. Until recently, high specific productivity of recombinant protein was limited to low cell density infected cultures of no more than 5×10⁵ cells/mL. In this paper, we show with a model protein, Protein Tyrosine Phosphatase 1C how high product yield can be maintained at high cell densities of 2×10⁶ cells/mL by a medium replacement strategy. This allows the production of as much as 90 mg/L of active recombinant protein per culture volume. Analysis of key limiting/inhibiting medium components showed that glucose addition along with pH control can yield the same productivity as a medium replacement strategy at high cell density in calcium-free DMEM. Finally, the above results were reproduced in 3L bioreactor suspension culture thereby establishing the scalability of this expression system. The process we developed is used routinely with the same success for the production of various recombinant proteins and viruses.Abbreviations CFDMEM calcium-free DMEM - CS bovine calf serum - hpi hours post-infection - J+ enriched Joklik medium - MLP major late promoter - MOI multiplicity of infection (# of infectious viral particle/cell) - q specific consumption rate (mole/cell.h) - pfu plaque forming unit (# of infectious viral particle) - Y yield (g/E6 cells or mole/cell)     

The sublethal effects of tebufenozide on the precopulatory and copulatory activities of Choristoneura fumiferana and C. rosaceana

The sublethal effects of tebufenozide, an ecdysone agonist, on the reproductive biology of Choristoneura fumiferana (Clem) and of Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), treated during the larval stage, were evaluated using two treatment methods: the force‐feeding method and the diet method. The percentage of mortality and the developmental time of survivors increased linearly with the concentration of tebufenozide used. This ecdysone analogue proved to be more toxic to C. fumiferana than to C. rosaceana. In C. rosaceana, the weight of males and females decreased proportionally with the dose ingested, but females were affected to a greater extent. This difference might be due to a greater consumption of the treated diet, or to a differential vulnerability to tebufenozide. Tebufenozide did not modify the pre‐copulatory activities associated with chemical communication in the females. However, the consumption of tebufenozide delayed ovarian maturation, causing a reduction in the fecundity of females. Treated males had smaller spermatophores and fewer eupyrene sperms in their bursa copulatrix and spermatheca, along with lower mating success. In C. fumiferana, tebufenozide delayed the females’ onset time of calling the first night after emergence, but did not affect the mean time spent calling or the production of the main component of the sex pheromone. The males showed significantly greater difficulty in executing oriented flight in a wind tunnel, although their mating success was not affected. We concluded that tebufenozide interferes with various aspects of the reproductive biology of males and females of C. fumiferana and C. rosaceana, including some pre‐copulatory behaviors associated with sex pheromone communication.     

Male larval nutrition in Choristoneura rosaceana (Lepidoptera: Tortricidae): an important factor in reproductive success

This study examines how Choristoneura rosaceana male quality, as determined by larval diet, age and mating history, affects the reproductive success of both sexes. While the size of the spermatophore produced at first mating increased linearly with male age, the frequency of mating was significantly higher for middle-aged males (2–4 days old) than younger (0–2 days old) or older (6–8 days old) individuals, when both sexes were fed on artificial diet. However, the duration of copulation was longer in couples with older than younger males. The observed age-related changes in spermatophore size had no significant effect on female longevity, fecundity or fertility, suggesting no direct relationship between male investment and spermatophore size under these experimental conditions. Different larval food sources (artificial diet, maple and hazelnut) did not affect the proportion of 2-day-old virgin males that mated; however, the proportion that remated was significantly higher for males reared on high-quality food (maple and artificial diet) than those on hazelnut, a poorer food source. There was a 5-fold decline in spermatophore size between the first and second matings on all diets, but female reproductive output was reduced by only 25%. In contrast, while the first spermatophore produced by males on hazelnut was 1.5 times smaller than those produced on maple and artificial diet, the fecundity of their mates was 40% less than those mated with high-quality virgin males. These results provide additional support to the idea that spermatophore size is not a valuable indicator of male quality. Most tethered females placed in the field during the first flight period mated with virgin males (based on the size of the spermatophore), suggesting that female choice exists in this species. These results are discussed in relation to the incidence of polyandry in naturally occurring populations of Choristoneura and the potential use of size and/or chemical cues by females to assess male quality.