The Effect of Antenatal Depression and Selective Serotonin Reuptake Inhibitor Treatment on Nerve Growth Factor Signaling in Human Placenta

Depressive symptoms during pregnancy are common and may have impact on the developing child. Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressant treatment, but unfortunately, these treatments can also negatively affect the behavioral development and health of a child during pregnancy. In addition, serotonin (5-HT) exerts neurotrophic actions with thus far not fully known effects in the offspring. The neurotrophic growth factor (NGF) is involved in neuronal cell survival and differentiation, and altered placenta levels have been found to increase the risk for pregnancy complications, similar to those found in women treated with SSRIs. We therefore investigated whether the NGF signaling pathway was altered in the placenta from women treated with SSRIs (n = 12) and compared them with placenta from depressed (n = 12) and healthy mothers (n = 12). Results from immunohistochemical stainings revealed that placental NGF protein levels of SSRI-treated women were increased in both trophoblasts and endothelial cells compared with depressed and control women. In addition, downstream of the NGF receptor TrkA, increased levels of the signaling proteins ROCK2 and phosphorylated Raf-1 were found in stromal cells and a tendency towards increased levels of ROCK2 in trophoblasts and endothelial cells in SSRI-treated women when compared to healthy controls. SSRI-treated women also displayed increased levels of phosphorylated ROCK2 in all placental cell types studied in comparison with depressed and control women. Interestingly, in placental endothelial cells from depressed women, NGF levels were significantly lower compared to control women, but ROCK2 levels were increased compared with control and SSRI-treated women. Taken together, these results show that the NGF signaling and downstream pathways in the placenta are affected by SSRI treatment and/or antenatal depression. This might lead to an altered placental function, although the clinical relevance of our findings still needs to be investigated.     

Formation and activity of covalent conjugates of poliovirus and ligands binding to cell surface structures

Disulfide-linked conjugates of poliovirus with streptavidin or concanavalin A were formed and the binding of the conjugates to mouse L cells that lack natural poliovirus receptors was studied. The conjugate with streptavidin was specifically bound to biotinylated L cells, but not to unmodified L cells. The conjugate with conA was bound to L cells in the absence of, but not in the presence of alpha-methyl mannoside. Incubation of L cells with bound conjugates did not produce virus, although the conjugates were highly infectious in HeLa cells, containing natural poliovirus receptors. This suggests that the artificially bound virus was unable to penetrate the L cells and start replication. The possibility that binding of the virus to the natural receptor is required for efficient infection is discussed.     

Algesia and local responses induced by neurokinin A and substance P in human skin and temporal muscle

Neurokinin A (NKA), substance P (SP) and the two peptides combined (SP + NKA) were injected intracutaneously on the forearm and into the temporal muscle of healthy volunteers. Pain intensity, cutaneous wheal and flare responses and tenderness of the temporal muscle were quantitated. SP but not NKA induced cutaneous pain. This relates the algesic effect of SP to the specific N-terminal amino acid sequence of the peptide, not shared by NKA. NKA, however, potentiated the algesic effect of SP as SP + NKA induced a significantly prolonged cutaneous pain sensation. Both peptides induced wheals, but only SP induced flare. These results confirm previous studies relating wheal formation to the identical C-terminal amino acid sequence of the two peptides and flare reaction to the N-terminal part of SP. Injections into the temporal muscle did not cause pain or tenderness.     

Mitogen Stimulation of Lymphocytes in Pigs with Hereditary Vitamin C Deficiency

Recently an inherited vitamin G deficiency in the pigs presumably based on an autosomal recessive gene was decribed* Homozygotes are in contrast to heterozygotes and normal pigs unable to synthesize ascorbic acid. In an experiment comprising 3 littermate pigs, 2 homozygous and 1 heterozygous for the vitamin C deficiency gene, the influence of ascorbic acid depletion, and repletion on mitogen stimulation of peripheral blood lymphocytes was studied. Ascorbic acid depletion of the vitamin C dependent pigs resulted in a rapid decline in plasma ascorbic acid. Response of lymphocytes to stimular tion with Concanavalin A (Con A) and phytohemagglutinin M (PHA) decreased more slowly reaching a minimum, which coincidedi with the occurrence of the first clinical symptoms of scurvy. Following resupplementation with vitamin C the plasma content of ascorbic acid rapidly returned to normal, while the lymphocyte response to Con A and PHA stimulation only gradually approached the initial values. The repletion with ascorbic acid caused a transitory increase in the response to pokeweed mitogen (PWM) stimulation. The significance of these findings in relation to the cellular immune system in normal pigs is discussed.     

Taxonomic studies of the genus Hypoxis in East Africa

East African material of the genus Hypoxis L. has preliminarily been divided into the heterogenous, probably apomictic H. obtusa Burch- complex (2n = 40–50, ca. 75, 76, ca. 85, >86, ca. 92, ca. 98, ca. 108, 130–135, 160–200) and 5 rather homogenous species: H. angustifolia Lam. (2n = 14, 28), H. goetzei Harms (2n = ca. 62), H. kilimanjarica Bak., H. malosana Bak. (2n = 14) and H. macrocarpa Holt & Staubo sp. nov. H. kilimanjarica is divided into ssp. kilimanjarica and ssp. prostrata Holt & Staubo ssp. nov.     

Effects of plant odor on oviposition by the black swallowtail butterfly,Papilio polyxenes (Lepidoptera: Papilionidae)

Black swallowtail females laid more eggs on plant models treated with contact stimulants and volatiles from carrot leaves than on models treated only with contact stimulants. The volatiles enhanced landing rates and females alighted more frequently on artificial leaves treated with host volatiles than on adjacent control leaves. Volatiles from cabbage, a nonhost, inhibited landing rates on artificial leaves treated with carrot contact stimulants. Examination of antennae revealed two major types of sensilla, believed to be olfactory in function. Electroantennogram preparations responded more strongly to carrot volatiles than to cabbage volatiles and several shared responses at particular retention times to carrot volatile components eluting from a gas chromatograph. Our results are consistent with a long-standing hypothesis that behavioral responses to essential oil components characteristic of the larval food plants have facilitated host shifts in the genus Papilio.     

T-DNA presence and opine production in tumors of Picea abies (L.) Karst induced by Agrobacterium tumefaciens A281

The hypervirulent Agrobacterium tumefaciens strain A281 formed frequent tumors (31%) on Picea abies (Norway spruce), an economically important tree species in Swedish forests. Three-month-old seedlings were inoculated and tumors were established that grew hormone-independently in culture. Tumors contained agropine and mannopine/mannopinic acid as determined by acid pH paper electrophoresis. In addition, DNA hybridization studies showed that the DNA from these tumor lines contained sequences homologous to Ti plasmid T-DNA, whereas wild-type spruce seedling DNA did not. These results suggest that Agrobacterium vectors can be used for gene transfer into this important forest species.