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1.
Lisa Rizzetto Gloria Giovannini Michael Bromley Paul Bowyer Luigina Romani Duccio Cavalieri 《PloS one》2013,8(2)
For over a century microbiologists and immunologist have categorized microorganisms as pathogenic or non-pathogenic species or genera. This definition, clearly relevant at the strain and species level for most bacteria, where differences in virulence between strains of a particular species are well known, has never been probed at the strain level in fungal species. Here, we tested the immune reactivity and the pathogenic potential of a collection of strains from Aspergillus spp, a fungus that is generally considered pathogenic in immuno-compromised hosts. Our results show a wide strain-dependent variation of the immune response elicited indicating that different isolates possess diverse virulence and infectivity. Thus, the definition of markers of inflammation or pathogenicity cannot be generalized. The profound understanding of the molecular mechanisms subtending the different immune responses will result solely from the comparative study of strains with extremely diverse properties. 相似文献
2.
Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration 下载免费PDF全文
Paola Riolo Nunzio Isidoro Sara Ruschioni Roxana L. Minuz Ferdinando Bin Roberto Romani 《Journal of morphology》2016,277(1):128-137
Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here “Antennal Dorsal Organs.” Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla‐like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla‐like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed. J. Morphol. 277:128–137, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
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The effects of extracellular K+ concentration ([K+]o) on the pH of cell sap, “bulk cytoplasm” and vacuole have been investigated in Elodea densa leaves under conditions of either low or high activity of the plasmalemma electrogenic H+ pump. Cell sap pH was evaluated directly in the cell sap expressed after freezing and thawing. Cytoplasmic and vacuolar pH were calculated by the weak base and weak acid distribution method, DMO and benzylamine appearing to be a suitable acid and base, respectively, for this purpose in this material. When added to the basal medium (no rapidly permeating ions present), 5 mM K+ induced an increase in intracellular pH, larger for the cell sap and the vacuole (about 0.2 units), and smaller but still significant for the cytoplasm (0.07 units). This alkalinizing effect of K+ was thus associated with a significant decrease in the pH difference across the tonoplast. The alkalinizing effect of K+ was markedly and synergistically enhanced by the presence of fusicoccin, a condition inducing a marked activation of H+ extrusion and of K+ uptake. The correlation between these effects of [K+]o on intracellular pH and those on H+ extrusion indicates that changes in extracellular K+ concentration, and thus in K+ influx, can influence cytoplasmic and vacuolar pH by modulating the rate of H+ extrusion by the plasmalemma H+ pump. 相似文献
6.
A Romani R Bergamaschi R Callieco V Cosi 《Bollettino della Società italiana di biologia sperimentale》1991,67(1):77-82
Ten healthy volunteers were submitted to an auditory oddball event related potentials (ERP) paradigm. Single trial 500 ms poststimulus ERPs (Pz, Cz, Fz--linked earlobes) along with the correspondent 1000 ms prestimulus EEG (O1-Cz) were stored. EEG epochs were submitted to spectral analysis and a slow wave index (SWI = delta + theta/total) was computed. Three selective ERP averages corresponding to low, medium and high SWI were computed. N2 latency was longer and P3a amplitude was lower in high SWI averages as compared to low SWI averages. 相似文献
7.
MgATP-dependent glucose 6-phosphate-stimulated Ca2+ accumulation in liver microsomal fractions. Effects of inositol 1,4,5-trisphosphate and GTP 总被引:3,自引:0,他引:3
A Benedetti R Fulceri A Romani M Comporti 《The Journal of biological chemistry》1988,263(7):3466-3473
Ca2+ release triggered by inositol 1,4,5-trisphosphate (IP3) and/or GTP has been studied with rough and smooth microsomes isolated from rat liver. Microsomes were loaded with Ca2+ in the presence of MgATP and in the presence or in the absence of glucose 6-phosphate (glucose-6-P) which markedly stimulated the MgATP-dependent Ca2+ accumulation in rough and smooth microsomes (5- and 10-fold, respectively). Upon addition of IP3 (5 microM), rough and smooth microsomes rapidly release a part (not exceeding 20%) of the Ca2+ previously accumulated both in the absence and in the presence of glucose-6-P. Under the same experimental conditions, inositol 1,3,4,5-tetrakisphosphate was ineffective in triggering any Ca2+ release. Upon addition of GTP (10 microM) both the microsomal fractions progressively release the Ca2+ previously accumulated in the presence of glucose-6-P, when 3% polyethylene glycol was also present. In the absence of polyethylene glycol, GTP released Ca2+ from rough microsomes only, and GTP plus IP3 caused a Ca2+ release which was the sum of the Ca2+ releases caused by GTP and IP3 independently. Both IP3 and GTP, added to microsomes at the beginning of the glucose-6-P-stimulated Ca2+ uptake, reduced the Ca2+ accumulation into rough and smooth microsomes without modifying the initial rate (3 min) of Ca2+ uptake. Also in these conditions, the effects of GTP and IP3 were merely additive. These results indicate that both rough and smooth liver microsomes are responsive to IP3 and GTP with respect to Ca2+ release and that IP3 and GTP likely act independently. 相似文献
8.
Ethylene production by auxin-deprived, suspension-cultured pear fruit cells in response to auxins, stress, or precursor 总被引:3,自引:2,他引:1 下载免费PDF全文
Auxin-deprived, mannitol-supplemented, suspension-cultured pear (Pyrus communis L. Passe Crassane) fruit cells produce large quantities (20-40 nanoliters ethylene per 106 cells per hour) of ethylene in response to auxins, CuCl2 or 1-amino-cyclopropane-1-carboxylic acid (ACC). Maximum rates of production are achieved about 12 hours after the addition of optimal amounts of indoleacetic acid (IAA), naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), 4 to 5 hours after the addition of CuCl2 and 1 to 2 hours after the addition of ACC. Supraoptimal concentrations of IAA result in a lag phase followed by a normal response. High concentrations of NAA and 2,4-D result in an early (4-5 hours) stress response and injury.
Continuous protein and RNA synthesis are essential for elaboration of the full IAA response; only protein synthesis is necessary for the response to CuCl2 and ACC. Based on polysomal states and rates of amino acid incorporation, CuCl2 partially inhibits protein synthesis while nonetheless stimulating ethylene production. In general, ethylene production by the pear cells resembles that of other plant systems. Some differences may reflect the sensitivity of the cells and are discussed. The relatively high levels of ethylene produced and the experimental convenience of the cultured cells should make them especially suitable for further investigations of ethylene production and physiology.
相似文献9.
The contribution of the alternative pathway to the respiration of suspension-cultured pear ( Pyrus communis cv. Passa Crasanne) cells was enhanced, often severalfold, within 2 to 4 days following the addition of cycloheximide, actinomycin D, or 2-(4-methyl-2,6-dinitroanalino)- N -methyl propionamide (D-MDMP). Concomitant inhibition of cellular protein synthesis by cycloheximide and actinomycin D was transient and incomplete. However, inhibition by D-MDMP was virtually complete (>97%) and persisted over several days. [35 S]-labelling and polyacrylamide gel separation indicated that cycloheximide precluded the appearance of discernable new proteins in mitochondria. Probes with monoclonal antibodies revealed a conservation of alternative oxidase protein levels in the mitochondria of inhibitor-treated cells. The data, appraised within the complexities of cell-culture dynamics, lead to the conclusion that the observed increases in capacity for cyanide-resistant respiration are the consequence, likely indirect, of inhibited protein synthesis with resultant retention and activation of constitutive alternative oxidase. 相似文献
10.
The effects of the growth in a medium containing NH4NO3 as nitrogensource were studied on cell sap pH, cytoplasmic pH and malatecontent in chl1, an Arabidopsis thaliana mutant impaired inchlorate and nitrate transport. In all the conditions testedthe pH of the cytoplasm in chl1 was more alkaline, and thatof the vacuole was more acidic as compared with those measuredin wt. Treatment with bafilomycin A1, a specific inhibitor ofthe vacuolar H+-ATPase, induced a small alkalinization of thevacuole, and a significant acidification of the cytoplasm, theseeffects being greater in chl1 than in wt. The greater responseof the mutant to bafilomycin Al suggests that, in the absenceof the inhibitor, the activity of the tonoplast H+-ATPase inchl1 is higher than in wt, this diversity being a possible reasonfor the differences in intracellular pH detected between thetwo strains. A possible role for the vacuolar H+-ATPase in regulatingthe cytoplasmic pH is discussed. (Received August 2, 1995; Accepted February 1, 1996) 相似文献