Nicotine inhibits cytokine production by placenta cells via NFkappaB: potential role in pregnancy-induced hypertension

Pregnancy-induced hypertension (PIH), also known as preeclampsia, is one of the major causes of maternal and fetal death. While the precise cause of PIH is not known, aberrant cytokine production and placenta participation are considered to be important factors. Gestational cigarette smoking, which is widely accepted to be harmful to both the mother and fetus, is protective against PIH. Based on the antiinflammatory activity of nicotine, the major component of cigarettes, we examined the effect of nicotine and other cholinergic agonists on placental inflammatory responses ex vivo. We observed that nicotine and other cholinergic agonists significantly suppress placenta cytokine production following stimulation. Placenta cells express the alpha7 nicotinic acetylcholine receptor (alpha7nAChR), and using cholinergic antagonists, we demonstrated that the antiinflammatory effect of nicotine and other cholinergic agonists is, in part, mediated through the nAChR pathway. By contrast, cholinergic stimulation had no effect on the expression of soluble fms-like tyrosine kinase (sFlt), an antiangiogenic substance implicated in maternal vascular dysfunction during PIH. Mechanistic studies reveal that cholinergic agonists exert their antiinflammatory effects through the NFkappaB pathway. Taken together, our results suggest that cholinergic agonists, including nicotine, may reduce cytokine production by placenta cells via NFkappaB to protect against PIH.     

The Mcf1 toxin induces apoptosis via the mitochondrial pathway and apoptosis is attenuated by mutation of the BH3-like domain

Photorhabdus are Gram-negative, nematode-vectored bacteria that produce toxins to kill their insect hosts. The expression of one of these, Makes caterpillars floppy 1 (Mcf1), is sufficient to allow Escherichia coli to survive within, and kill, caterpillars which are otherwise able to clear E. coli infection. Mcf1 treated caterpillars show rapid loss of body turgor (the 'floppy' phenotype) and death is associated with massive apoptosis of both the midgut epithelium and insect phagocytes. Mammalian tissue culture cells treated with Mcf1 also display key features of apoptosis including zeiosis, apoptotic nuclear morphology, DNA laddering, activation of the effector caspase-3 and PARP cleavage. As Mcf1 carries a single BH3-like domain, here we investigate the hypothesis that this toxin promotes apoptosis via the mitochondrial pathway by mimicking a BH3 domain-only protein. Consistent with this hypothesis, a double mutant within the BH3-like domain causes a dramatic decline in apoptosis. Mcf1 also alters mitochondrial membrane potential and triggers the release of cytochrome c. Cells overexpressing Bcl-x(L), an anti-apoptotic Bcl-2 family member, are resistant to Mcf1-mediated apoptosis, as are cells deficient in Bax. In addition, translocation of Bax to the mitochondrion is observed in response to Mcf1 treatment. Together, these results show that Mcf1 mediates apoptosis via the mitochondrial pathway, and are consistent with the hypothesis that the BH3-like domain in Mcf1 is a functional requirement for the pro-apoptotic activity of Mcf1.     

Evolution of the hymenopteran megaradiation

The Hymenoptera--ants, bees and wasps--represent one of the most successful but least understood insect radiations. We present the first comprehensive molecular study spanning the entire order Hymenoptera. It is based on approximately 7 kb of DNA sequence from 4 gene regions (18S, 28S, COI and EF-1α) for 116 species representing all superfamilies and 23 outgroup taxa from eight orders of Holometabola. Results are drawn from both parsimony and statistical (Bayesian and likelihood) analyses, and from both by-eye and secondary-structure alignments. Our analyses provide the first firm molecular evidence for monophyly of the Vespina (Orussoidea+Apocrita). Within Vespina, our results indicate a sister-group relationship between Ichneumonoidea and Proctotrupomorpha, while the stinging wasps (Aculeata) are monophyletic and nested inside Evaniomorpha. In Proctotrupomorpha, our results provide evidence for a novel core clade of proctotrupoids, and support for the recently proposed Diaprioidea. An unexpected result is the support for monophyly of a clade of wood-boring sawflies (Xiphydrioidea+Siricoidea). As in previous molecular studies, Orussidae remain difficult to place and are either sister group to a monophyletic Apocrita, or the sister group of Stephanidae within Apocrita. Both results support a single origin of parasitism, but the latter would propose a controversial reversal in the evolution of the wasp-waist. Generally our results support earlier hypotheses, primarily based on morphology, for a basal grade of phytophagous families giving rise to a single clade of parasitic Hymenoptera, the Vespina, from which predatory, pollen-feeding, gall-forming and eusocial forms evolved.     

Trachymolgus purpureus sp. n., an armored snout mite (Acari, Bdellidae) from the Ozark highlands: morphology, development, and key to Trachymolgus Berlese

Trachymolgus purpureus Fisher & Dowling sp. n. is described from the Ozark highlands of North America. A diversity of imaging techniques are used to illustrate the species including low-temperature scanning electron microscopy (LT-SEM), stereomicrography, compound light micrography, and digitally created line drawings. Developmental stages (larva, nymphs, and adult) and morphology are illustrated and discussed, and terminological corrections are suggested. Trachymolgus recki Gomelauri, 1961 is regarded as being described from tritonymphs. A key to Trachymolgus is presented.     

Alginate beads as a storage, delivery and containment system for genetically modified PCB degrader and PCB biosensor derivatives of Pseudomonas fluorescens F113

Aims: Pseudomonas fluorescens F113Rifpcb is a genetically engineered rhizosphere bacterium with the potential to degrade polychlorinated biphenyls (PCBs). F113Rifpcbgfp and F113L::1180gfp are biosensor strains capable of detecting PCB bioavailability and biodegradation. The aim of this paper is to evaluate the use of alginate beads as a storage, delivery and containment system for use of these strains in PCB contaminated soils. Methods and Results: The survival and release of Ps. fluorescens F113Rifpcb from alginate beads were evaluated. Two Ps. fluorescens F113‐based biosensor strains were encapsulated, and their ability to detect 3‐chlorobenzoate (3‐CBA) and 3‐chlorobiphenyl (3‐CBP) degradation in soil was assessed. After 250 days of storage, 100% recovery of viable F113Rifpcb cells was possible. Amendments to the alginate formulation allowed for the timed release of the inoculant. Encapsulation of the F113Rifpcb cells provided a more targeted approach for the inoculation of plants and resulted in lower inoculum populations in the bulk soil, which may reduce the risk of unintentional spread of these genetically modified micro‐organisms in the environment. Encapsulation of the biosensor strains in alginate beads did not interfere with their ability to detect either 3‐CBA or 3‐CBP degradation. In fact, detection of 3‐CBP degradation was enhanced in encapsulated biosensors. Conclusions: Alginate beads are an effective storage and delivery system for PCB degrading inocula and biosensors. Significance and Impact of the Study: Pseudomonas fluorescens F113Rifpcb and the F113 derivative PCB biosensor strains have excellent potential for detecting and bioremediation of PCB contaminated soils. The alginate bead delivery system could facilitate the application of these strains as biosensors.     

Monoaminergic neurons of the mudpuppy retina

Summary The mudpuppy retina was investigated with the histofluorescence method of Falck and Hillarp in normal animals and in animals injected intraocularly with -methylnoradrenaline, 5,6-dihydroxytryptamine, or a combination of the two drugs. Catecholaminergic amacrine cells were found to form a thin layer of terminals at the border between the inner nuclear and the inner plexiform layers. Catecholaminergic interplexiform cells were not found. Indoleamine-accumulating amacrine cells were also observed. They are fifteen to twenty times more numerous than the catecholaminergic cells, and their terminals occur diffusely throughout the inner plexiform layer. In a number of eyes the majority of the indoleamine-accumulating terminals were eliminated with intraocular injections of the neurotoxin, 5,7-dihydroxytryptamine, but the reproducibility of this effect was not consistent. Intravitreal injections of 5,6-dihydroxytryptamine were used to label both types of neurons for electron microscopy. They were found to make conventional type synapses on amacrine cells and, less frequently, on bipolar cells.     

Colonization behaviour of Pseudomonas fluorescens and Sinorhizobium meliloti in the alfalfa (Medicago sativa) rhizosphere

The colonization ability of Pseudomonas fluorescens F113rif in alfalfa rhizosphere and its interactions with the alfalfa microsymbiont Sinorhizobium meliloti EFB1 has been analyzed. Both strains efficiently colonize the alfalfa rhizosphere in gnotobiotic systems and soil microcosms. Colonization dynamics of F113rif on alfalfa were similar to other plant systems previously studied but it is displaced by S. meliloti EFB1, lowering its population by one order of magnitude in co-inoculation experiments. GFP tagged strains used to study the colonization patterns by both strains indicated that P. fluorescens F113rif did not colonize root hairs while S. meliloti EFB1 extensively colonized this niche. Inoculation of F113rif had a deleterious effect on plants grown in gnotobiotic systems, possibly because of the production of HCN and the high populations reached in these systems. This effect was reversed by co-inoculation. Pseudomonas fluorescens F113 derivatives with biocontrol and bioremediation abilities have been developed in recent years. The results obtained support the possibility of using this bacterium in conjunction with alfalfa for biocontrol or rhizoremediation technologies.