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M. F. Martínez M. S. Santini M. M. Kowalewski O. D. Salomn 《Medical and veterinary entomology》2019,33(3):367-374
Multiple species of Phlebotominae are vectors of Leishmania (Protozoa: Trypanosomatidae), which causes visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). To describe the Phlebotominae (Diptera: Psychodidae) related to the environments of black and gold howler monkeys Alouatta caraya (Humbodlt, 1812) (Primates: Atelidae), potential vectors were sampled in different landscapes and vertical strata of sleeping trees. Phlebotomine captured between December 2011 and March 2012 (2365 individuals) belonged to eight species, of which Nyssomyia neivai (Pinto, 1926) (61.4%) and Migonemyia migonei (França, 1920) (18.73%) were the most abundant, and Ny. withmani was recorded for the first time in the Chaco province. In the ‘peri‐domestic’ landscape, the phlebotomine were mainly captured in henhouses (78.7%), whereas the tree canopy in ‘rural’ and ‘wild’ landscapes yielded 31.2% and 29.1% of the phlebotomine, respectively. A significant association between the type of landscape and the species of phlebotomine was observed by multivariate analysis. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Mg. migonei were associated with ‘peri‐domestic’ landscape, and Ny. neivai was associated with the ‘wild’ landscape. The results of this prospective study suggest that the interaction between phlebotomine and A. caraya could be a key factor with respect to understanding the epidemiology of leishmaniasis. 相似文献
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Involvement of a protein with molybdenum cofactor in the in vitro activation of nitrate reductase from a chlA mutant of Escherichia coli K12 总被引:1,自引:0,他引:1
Chlorate-resistant mutants are pleiotropically defective in molybdoenzyme activities. The inactive derivative of the molybdoenzyme, respiratory nitrate reductase (nitrite: (acceptor) oxidoreductase, EC 1.7.99.4), which is present in cell-free extracts of chlA mutants can be activated by addition of purified protein PA, the presumed active product of the chlA+ locus, but the activity of the purified protein PA is low, since comparatively large amounts of protein PA are required for the activation. Addition of 10 mM tungstate to the growth medium of a chlBchlC double mutant leads to inactivation of both the molybdenum cofactor and protein PA. Protein PA prepared from such cells was unable to potentiate the in vitro activation of nitrate reductase present in the soluble fraction of a chlA mutant. Quantitation of inactive protein PA was determined immunologically using protein PA-specific antiserum. When a heat-treated extract of a wild-type strain was added to purified protein PA or to the supernatant fraction of a chlBchlC double mutant grown with tungstate, a large stimulation in the ability of these preparations to activate chlA nitrate reductase was found. We equate the activator of protein PA with molybdenum cofactor because: (1) both are absent from heated extracts of tungstate-grown chlBchlC double mutant and cofactor defective chlA and chlE mutants; (2) both are present in heated extracts of wild-type strain; and (3) they behave identically on molecular-sieve columns. 相似文献
5.
M T Santini L Guidoni V Viti P L Indovina 《Physiological chemistry and physics and medical NMR》1992,24(2):89-96
High resolution proton NMR was used to study the cell surface molecular events which take place during in vitro myoblast differentiation and fusion. The CH3 and (CH2)n spectral signals were followed throughout in vitro myogenic development. The results show that although both the T1 and T2 relaxation times of the CH3 and (CH2)n groups are sensitive to the fusion process, T1 is the most sensitive. Both T1 of CH3 and (CH2)n increased before fusion indicating a higher degree of molecular motion and then returned to their original values. These results demonstrate how mobile lipid domains observed with proton NMR can be used to study the changes taking place during myoblast differentiation, particularly myoblast membrane fusion. 相似文献
6.
Genetic determinants of glutamine synthetase inDrosophila melanogaster: A gene for glutamine synthetase I resides in the 21B3-6 region 总被引:1,自引:0,他引:1
Corrado Caggese Ruggiero Caizzi Maria Pia Bozzetti Paolo Barsanti Ferruccio Ritossa 《Biochemical genetics》1988,26(9-10):571-584
Recombinational and deletion mapping of electrophoretic variants of the glutamine synthetase I isozyme (GSI) in Drosophila melanogaster locates the gene in the 21B region on the second chromosome. We have conducted a genetic analysis of the region extending cytologically from 21A to 21B4-6. Recessive lethal mutations were generated by ethyl methanesulfonate (EMS) and ethyl nitrosourea (ENU) mutagenesis and by hybrid dysgenesis (HD). These lethals fall into seven functional groups, which were partially ordered by complementation with cytologically defined deficiencies of this region generated by hybrid dysgenesis. Two of the EMS- and two of the ENU-induced lethals fulfill biochemical criteria expected for null alleles of the GSI gene. 相似文献
7.
T Douss R Santini P Deschaux H Pacheco 《Comptes rendus des séances de la Société de biologie et de ses filiales》1985,179(3):299-306
A suspension of 10(7) melanoma cells, submitted to microwave hyperthermia (2,450 MHz, 20 minutes, 44 degrees C) leads to a partial protection in mice inoculated 26 days afterwards with a suspension of 10(7) active cells of B16 melanoma (95% vitality). The period of 26 days between the two injections corresponds to the moment where the sera antibodies have an highest level. The kinetics of the primary response of the humoral immunity shows that B16 melanoma proliferation and number of deads can be related to an hypogammaglobulinemia. 相似文献
8.
Walter Malorni Pietro L. Indovina Giuseppe Arancia Stefania Meschini Maria T. Santini 《In vitro cellular & developmental biology. Plant》1990,26(4):399-410
Summary This paper describes the microscopic evidence supporting a cesium-induced delay in the fusion of chick embryo myoblast membranes
during in vitro myogenic differentiation. We have recently demonstrated that the sharp decrease in the conductivity and permittivity
of the membranes of these myogenic cells at the time of fusion is delayed 30 h by the addition of cesium to the culture medium
(Santini et al., Biochim. Biophys. Acta 945:56–64; 1988). We report here that this delay in fusion is substantiated by direct
microscopic observation and that cesium also induces ultrastructural changes in the myoblast cells themselves. Possible mechanisms
by which cesium may cause both the delay in fusion as well as the ultrastructural changes observed are discussed.
This investigation was partially supported by an Italian Consiglio Nazionale delle Ricerche grant 85.00.304.02 (to P. L. I.). 相似文献
9.
Homing to a more or less permanent scar after each foragingexcursion is a common movement pattern among intertidal gastropodsand chitons; however, details of the timing and spacing of foragingactivity have been investigated only in a few species. The presentstudy analyzes the short-term behavior of the limpet Patellarustica along the Tyrrhenian coast, Italy, using a motographictechnique to assess the fine organization of its foraging duringfavorable periods of sea roughness. P. rustica becomes activeonce the upper midlittoral is well splashed. It alternates foragingexcursions and resting at home with a periodicity slightly longerthan 12 h, suggesting a tidal-diel pattern. However, periodogramanalysis of the sea level oscillations during the study periodsrevealed no such rhythmicity because tidal oscillations werehidden by irregular variations caused by waves. As a resultof this time partitioning, limpets move, on average, less than50% of their potential activity time. Time partitioning maybe highly adaptive in reducing potential risks. Nevertheless,in the absence of clear external driving cues, the significanceof a very regular and apparently tidal pattern, fairly synchronousamong the different specimens, remains to be explained. Theactivity of P. rustica during each excursion is organized intothree parts: the outgoing journey during which grazing activityprogressively increases, a central part characterized by intensegrazing, and the return characterized by fast displacement anda more or less consistent trail following. Limpets head forrandom directions to reach foraging grounds in successive excursions,showing only a slight avoidance of the direction taken duringthe previous outward journey. This pattern produces a spatialscattering of grazing activity, allowing efficient exploitationof grazing areas distributed radially around home during subsequentexcursions. 相似文献
10.
Vittorio Moretto Fernando Formaggio Marco Crisma Gian Maria Bonora Claudio Toniolo Ettore Benedetti Antonello Santini Michele Saviano Benedetto Di Blasio Carlo Pedone 《Journal of peptide science》1996,2(1):14-27
A complete series of terminally blocked, monodispersed homo-oligopeptides (to the pentamer level) from the sterically demanding, medium-ring alicyclic Cα,α-disubstituted glycine 1-aminocyclooctane-1-carb oxylic acid (Ac8c), and two Ala/Ac8c tripeptides, were synthesized by solution methods and fully characterized. The preferred conformation of all the oligopeptides was determined in deuterochloroform solution by IR absorption and 1H-NMR. The molecular structures of the amino acid derivative Z-Ac8c-OH, the dipeptide pBrBz- (Ac8c)2-OH and the tripeptide pBrBz-(Ac8c)3-OtBu were assessed in the crystal state by X-ray diffraction. Conformational energy computations were performed on the monopeptide Ac-Ac8c-NHMe. Taken together, the results obtained strongly support the view that the Ac8c residue is an effective β-turn and helix former. A comparison is also made with the conformational preferences of α-aminoisobutyric acid, the prototype of Cα, α-disubstituted glycines, and of the other members of the family of 1-aminocycloalkane-1-carboxylic acids (Acnc, with n=3, 5–7) investigated so far. The implications for the use of the Ac8c residue in peptide conformational design are considered. 相似文献