Changes in airway resistance induced by nasal inhalation of cold dry, dry, or moist air in normal individuals

Fontanari, Pierre, Henri Burnet, Marie CarolineZattara-Hartmann, and Yves Jammes. Changes in airway resistanceinduced by nasal inhalation of cold dry, dry, or moist air in normalindividuals. J. Appl. Physiol. 81(4):1739-1743, 1996.Nasopulmonary bronchomotor reflexes elicited bymechanical or irritant stimulation of the nose have been described inanimals and asthmatic patients. However, few studies were devoted tothe consequences of nasal breathing of cold and dry air or of only dryor only moist air on the bronchomotor control in normal individuals.The present study reported changes in interruption resistance (Rint)measured during eupneic breathing of moderately cold (4 or10°C) and dry [0.3% relative humidity (RH)] airor of room air at 23°C that is either dry (0.3% RH) or moist (97%RH). Nasal inhalation of cold (4°C) dry air or of only dryair significantly increased baseline Rint value (17 and 21%,respectively) throughout the 15-min test periods. The response to cold was significantly accentuated when the air temperature was lowered to 10°C (42%). After nasal anesthesia orinhalation of a cholinergic antagonist, cold air did not induce achange in Rint. Nasal inhalation of moist room air had no effect. No Rint changes were measured during oral breathing of the three testagents. It is concluded that the activation of cold receptors orosmoreceptors in the nasal mucosa induces protective bronchoconstrictor responses in normal individuals.

     

Somatic embryogenesis and plant regeneration in garden leek

High frequency plant regeneration via somatic embryogenesis has been induced from in vitro shoot-base cultures of seedlings of garden leek (Allium porrum L.). Four main steps are involved in the procedure using BDS medium:

- shoot multiplication with 17.6 mM benzyladenine;

- induction of nodular callus from the in vitro shoot base with 9 mM 2,4-dichlorophenoxyacetic acid;

- initiation of embryogenic callus from nodular callus with 9 mM 2,4-dichlorophenoxyacetic acid +7.6 mM abscisic acid;

- plant regeneration from embryogenic callus with 9.8 mM N⁶-(2-isopentenyl)adenine.

The presence of 2,4-dichlorophenoxyacetic acid in the medium and light conditions were shown to be essential for nodular callus induction and somatic embryogenesis. Abscisic acid was not a prerequiste for somatic embryogenesis, but it significantly increased the frequency.     

Axonal Transport Characteristics of Gangliosides in Sensory Axons of Rat Sciatic Nerve

The distribution of axonally transported gangliosides and glycoproteins along the sciatic nerve was examined from 3 h to 4 weeks following injection of[3H]glucosamine into the fifth lumbar dorsal root ganglion of adult rats. Incorporation of labeled precursor into these glycoconjugates reached a maximal level in the ganglion within 6 h. Outflow patterns of radioactivity for glycoproteins showed a well-defined crest with a transport rate of approximately 330 mm/day. In contrast, the crest of transported gangliosides was continuously attenuated, implying a significant deposition along the axon, and an alternative method of calculating velocity was required. Analysis of accumulation of labeled material at double ligatures demonstrated both anterograde and retrograde transport of glycoproteins and gangliosides and allowed for the calculation of an anterograde transport rate of about 270 mm/day for each. Additional evidence of ganglioside transport is provided in that the TLC pattern of transported radioactive gangliosides accumulating at a ligature is significantly different from the pattern seen in the dorsal root ganglion or following intraneural administration of the labeled precursor. These data indicate that gangliosides are transported at the same rapid rate as glycoproteins but are subject to a more extensive exchange with stationary material than are glycoproteins.     

Carrier Transport and Recombination in Efficient “All‐Small‐Molecule” Solar Cells with the Nonfullerene Acceptor IDTBR

Reaching device efficiencies that can rival those of polymer‐fullerene Bulk Heterojunction (BHJ) solar cells (>10%) remains challenging with the “All‐Small‐Molecule” (All‐SM) approach, in part because of (i) the morphological limitations that prevail in the absence of polymer and (ii) the difficulty to raise and balance out carrier mobilities across the active layer. In this report, the authors show that blends of the SM donor DR3TBDTT (DR3) and the nonfullerene SM acceptor O‐IDTBR are conducive to “All‐SM” BHJ solar cells with high open‐circuit voltages (V_OC) >1.1 V and PCEs as high as 6.4% (avg. 6.1%) when the active layers are subjected to a post‐processing solvent vapor‐annealing (SVA) step with dimethyl disulfide (DMDS). Combining electron energy loss spectroscopy (EELS) analyses and systematic carrier recombination examinations, the authors show that SVA treatments with DMDS play a determining role in improving charge transport and reducing non‐geminate recombination for the DR3:O‐IDTBR system. Correlating the experimental results and device simulations, it is found that substantially higher BHJ solar cell efficiencies of >12% can be achieved if the IQE and carrier mobilities of the active layer are increased to >85% and >10^?4 cm² V^?1 s^?1, respectively, while suppressing the recombination rate constant k to <10^?12 cm³ s^?1.     

S-adenosyl-l-methionine inhibits phosphoinositide metabolism in the rat brain synaptosomal suspensions

S-adenosyl-l-methionine (AdoMet) has been reported to affect events linked to noradrenergic neurotransmission. In the present work, we studied the effect of AdoMet on norepinephrine (NE)-stimulated inositol phosphate production in³H-inositol-labelled crude synaptosomal suspensions of rat brain. AdoMet (50–1000 M) decreased both the synthesis of labelled polyphosphoinositide (30–50%) and the release of inositol mono- and bisphosphate (40–50%). The AdoMet effect was not dependent on NE concentration (10–1000 M), suggesting that the inhibition of inositol phosphate release was not the result of a modification of the norepinephrine binding to its receptor sites. S-adenosyl-L-homocysteine (AdoHcy) (1 mM) an inhibitor of methyltransferase activities, partially inhibited (70%) the AdoMet (0.1 mM) effect, indicating that the methylation processes cannot explain all the effects observed. We conclude that, in addition to previously reported effects of AdoMet on NE transport, AdoMet may reduce NE-linked intracellular signalling.     

Human reciprocal translocations: is the unbalanced mode at birth predictable?

Two methods of prediction for the risk of unbalance at birth were tested on a large data base of reciprocal translocation (1376 families): the pachyten diagram predictive method (PDPmethod) and the discriminant method (Dmethod). These method succeeded in correctly predicting the segregation mode in 66% of the data for the PDPmethod and in 80% of the data for the Dmethod. The quality of chromosome material (in particular R bands) must be taken into account for more accurate prediction. Some difficulties still exist in predicting the 31 tertiary segregation mode, which can frequently be incorrectly classified as the adjacent 1 mode.     

A nuclear export signal and phosphorylation regulate Dok1 subcellular localization and functions

Dok1 is believed to be a mainly cytoplasmic adaptor protein which down-regulates mitogen-activated protein kinase activation, inhibits cell proliferation and transformation, and promotes cell spreading and cell migration. Here we show that Dok1 shuttles between the nucleus and cytoplasm. Treatment of cells with leptomycin B (LMB), a specific inhibitor of the nuclear export signal (NES)-dependent receptor CRM1, causes nuclear accumulation of Dok1. We have identified a functional NES (348LLKAKLTDPKED359) that plays a major role in the cytoplasmic localization of Dok1. Src-induced tyrosine phosphorylation prevented the LMB-mediated nuclear accumulation of Dok1. Dok1 cytoplasmic localization is also dependent on IKKbeta. Serum starvation or maintaining cells in suspension favor Dok1 nuclear localization, while serum stimulation, exposure to growth factor, or cell adhesion to a substrate induce cytoplasmic localization. Functionally, nuclear NES-mutant Dok1 had impaired ability to inhibit cell proliferation and to promote cell spreading and cell motility. Taken together, our results provide the first evidence that Dok1 transits through the nucleus and is actively exported into the cytoplasm by the CRM1 nuclear export system. Nuclear export modulated by external stimuli and phosphorylation may be a mechanism by which Dok1 is maintained in the cytoplasm and membrane, thus regulating its signaling functions.