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71.
Svobodová M Alten B Zídková L Dvorák V Hlavacková J Mysková J Seblová V Kasap OE Belen A Votýpka J Volf P 《International journal for parasitology》2009,39(2):251-256
Transmission of cutaneous leishmaniasis (CL) caused by Leishmania infantum was studied in South Anatolia, Turkey. Small, non-ulcerating lesions prevailed and patients were negative in rK39 tests for antibody detection for human visceral leishmaniasis (VL). The most abundant sand fly species, Phlebotomus tobbi, was found positive for Leishmania promastigotes with a prevalence of 1.4% (13 out of 898 dissected females). The isolated strains were identical with those obtained from patients with CL and were typed as L. infantum. Phylogenetic analysis revealed similarity to MON-188 and a clear difference from the MON-1 clade. Blood-meal identification showed that P. tobbi feeds preferentially on cattle and humans. This finding, the high number of CL patients and relative scarcity of dogs in the focus, suggests that the transmission cycle could be anthroponotic. 相似文献
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Cepicka I 《European journal of protistology》2011,47(1):10-15
The genus Rhizomastix contains five species of amoeboflagellates with a single anterior flagellum, which live as intestinal symbionts of insects and amphibians. Though established in 1911, Rhizomastix has been neglected for decades and its phylogenetic position is uncertain. This paper describes the morphology of the first cultivated strain of Rhizomastix. The organism was isolated from an argentine horned frog and differs from the known Rhizomastix species by the presence of biflagellate cells. The isolate is described as Rhizomastix biflagellata sp. nov. A possible relationship of Rhizomastix to Archamoebae is discussed. 相似文献
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Hana Ujcikova Katerina Dlouha Lenka Roubalova Miroslava Vosahlikova Dmytro Kagan Petr Svoboda 《Biochimica et Biophysica Acta (BBA)/General Subjects》2011
Background
Activation of adenylyl cyclase (AC) by prolonged exposure of mammalian organism to morphine was demonstrated in previous studies of mechanism of action of this drug. However, expression level of individual AC isoforms was not analyzed in crucial cell structure, plasma membrane (PM).Methods
Rats were adapted to morphine for 10 days and sacrificed 24 h (group + M10) or 20 days (+ M10/−M20) after the last dose. Control animals were sacrificed in parallel with morphine-treated (groups − M10 and (− M10/−M20)). Percoll®-purified PM were isolated from brain cortex and analyzed by immunoblotting and specific radioligand binding.Results
ACI (ACII) was increased 8× (2.5×) in morphine-adapted rats (+ M10) when compared with controls (− M10). Increase of ACI and II by long-term adaptation to increasing doses of morphine represented a specific effect as the amount of ACIII–ACIX, of prototypical PM marker, Na, K-ATPase and of trimeric G protein α and β subunits was unchanged. Increase of ACI and II was not detected in PM isolated from group (+ M10/−M20). Thus, the marked increase of ACI and ACII faded away 20 days since the last dose of morphine.Conclusions
We assume that the specific increase in expression level of ACI and ACII in brain cortex of morphine-adapted rats proceeds as a compensatory, homeostatic response to prolonged exposure to inhibitory drug, morphine.General significance
Our findings demonstrate that the dramatic and specific change of the crucial component of the opioid receptor cascade in brain cortex, manifested as an increase in PM level of ACI and II, is reversible. 相似文献74.
Protein composition of membrane domains prepared by three different procedures (mechanical homogenization, alkaline treatment
with 1 M Na2CO3[pH 11.0], or extraction with nonionic detergent Triton X-100), and isolated from the bulk of plasma membranes by flotation
on equilibrium sucrose density gradients, was analyzed by two-dimensional (2D) electrophoresis and compared in preparations
from control (quiescent) and agonist-stimulated human embryonic kidney cells (HEK)293 or S49 cells. HEK293 cells (clone e2m11)
stably expressing high levels of thyrotropin-releasing hormone receptor and G11α protein were stimulated by thyrotropin-releasing hormone and S49 lymphoma cells by the β-adrenergic receptor agonist isoprenaline.
Whereas sustained exposure (16h) of both cell lines to the appropriate hormones led to substantial cellular redistribution
and downregulation of the cognate G proteins (Gqα/G11α and Gsα, respectively), the distribution and levels of nonstimulated Gi proteins remained unchanged. The 2D electrophoretic analysis of membrane domains distinguished approx 150–170 major proteins
in these structures and none of these proteins was significantly altered by prolonged agonist stimulation. Furthermore, specific
immunochemical determination of a number of plasma membrane markers, including transmembrane and glycosyl-phosphatidylinositol-anchored
peripheral proteins, confirmed that their detergent-extractability/solubility was not influenced by hormone treatment. Collectively,
our present data indicate that sustained hormone stimulation of target cells does not alter the basic protein composition
of membrane domain/raft compartments of the plasma membrane in spite of marked changes proceeding in a given signaling cascade. 相似文献
75.
A new species, Bosmina tripurae is described from South India. The species shares some of the morphological traits with Bosmina
fatalis from East and SE Asia, and two other species described recently from North America. They all form a subgeneric group
established earlier: subgenus Sinobosmina Lieder 1957. Parthenogenetic females of the new species are superficially similar
to the species Bosmina longirostris, which occurs on Indian subcontinent, only in northern high mountain lakes. All reports
of the latter species from Indian lowlands are either Bosmina tripurae or some other not yet described species.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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In two archaeognathans, Lepismachilis notata and Machilis hrabei, the midgut epithelium and processes of its regeneration and degeneration have been described at the ultrastructural level. In both analysed species, the midgut epithelium is composed of epithelial and regenerative cells (regenerative nests). The epithelial cells show distinct regionalization in organelles distribution with the basal, perinuclear, and apical regions being distinguished. Degeneration of epithelial cells proceeds in a necrotic way (continuous degeneration) during the entire life of adult specimens, but just before each moult degeneration intensifies. Apoptosis has been observed. Regenerative cells fulfil the role of midgut stem cells. Some of them proliferate, while the others differentiate into epithelial cells. We compared the organisation of the midgut epithelium of M. hrabei and L. notata with zygentoman species, which have just been described. 相似文献
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Two microtubule-containing structures are implicated in dorsoventral polarization of the frog egg, and we examined the relationship
between them. The sperm aster provides a directional cue for a cortical rotation specifying polarity, and a vegetal cortical
array of parallel microtubules is likely part of the rotational machinery. The growing aster has an accumulation of microtubules
marking the path of the sperm pronucleus, and its microtubules extend into the egg cortex as well as the cytoplasm. To test
whether the vegetal parallel array was an extension of astral cortical growth, fertilized or activated eggs were bisected
into animal and vegetal fragments. The vegetal fragments formed parallel arrays, even when isolated within a few minutes of
egg activation. Neither the sperm centrosome nor another microtubule organizing center in the animal half of the egg is required
for formation of the parallel array, but some animal half activity is involved in its disappearance.
Correspondence to: R.P. Elinson 相似文献