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Motility Patterns (motility + pattern)
Selected AbstractsTyrphostin-A47 inhibitable tyrosine phosphorylation of flagellar proteins is associated with distinct alteration of motility pattern in hamster spermatozoaMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2006Daniel Mariappa Abstract To acquire fertilizing potential, mammalian spermatozoa must undergo capacitation and acrosome reaction. Our earlier work showed that pentoxifylline (0.45 mM), a sperm motility stimulant, induced an early onset of hamster sperm capacitation associated with tyrosine phosphorylation of 45,80 kDa proteins, localized to the mid-piece of the sperm tail. To assess the role of protein tyrosine phosphorylation in sperm capacitation, we used tyrphostin-A47 (TP-47), a specific protein tyrosine kinase inhibitor. The dose-dependent (0.1,0.5 mM) inhibition of tyrosine phosphorylation by TP-47 was associated with inhibition of hyperactivated motility and 0.5 mM TP-47-treated spermatozoa exhibited a distinct circular motility pattern. This was accompanied by hypo-tyrosine phosphorylation of 45,60 kDa proteins, localized to the principal piece of the intact-sperm and the outer dense fiber-like structures in detergent treated-sperm. Sperm kinematic analysis (by CASA) of spermatozoa, exhibiting circular motility (at 1st hr), showed lower values of straight line velocity, curvilinear velocity and average path velocity, compared to untreated controls. Other TP-47 analogues, tyrphostin-AG1478 and -AG1296, had no effect either on kinematic parameters or sperm protein tyrosine phosphorylation. These studies indicate that TP-47-induced circular motility of spermatozoa is compound-specific and that the tyrosine phosphorylation status of 45,60 kDa flagellum-localized proteins could be key regulators of sperm flagellar bending pattern, associated with the hyperactivation of hamster spermatozoa. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Oxyntomodulin and glicentin are potent inhibitors of the fed motility pattern in small intestineNEUROGASTROENTEROLOGY & MOTILITY, Issue 4 2004S. Pellissier Abstract, Glicentin (GLIC) and oxyntomodulin (OXM or GLIC 33-69) are gut hormones which regulate digestion. They are known to reduce digestive secretions and to delay gastric emptying. Their biological activities on intestinal motility are still unknown. The effect of a systemic GLIC or OXM increase was investigated in rats on the food intake, the postprandial myoelectrical activity of small intestine and the orocaecal transit. An OXM or GLIC i.v. infusion was applied during the 5 min preceding food onset and during the first 15 min of food intake. This determined a three- to fourfold increase of the preprandial OXM,GLIC level. The OXM or GLIC plasma increase did not modify food intake. OXM infusion slowed down gastric emptying when the stomach contained 3/4 of the ingested food (before T 3 h). The quantity of food delivered in jejunum was subsequently smaller (P < 0.05). In the small intestine, the duration of postprandial myoelectrical activity (50,60 min g,1 of ingested food) was reduced by 70% (P < 0.001) on duodenum or jejunum and by 54% (P < 0.01) on ileum in OXM-treated rats. An interdigestive motility profile was settled and an acceleration of both gastric emptying and transit rate was thereafter evidenced (after T 3 h). GLIC also reduced the duration of the postprandial myoelectrical activity on duodenum and jejunum (65 and 63% respectively, P < 0.05), but was not as efficient as OXM on ileum. In pathological states such as acute adult gastroenteritis, OXM and GLIC exhibit a two- to fivefold increase in their plasma concentrations. The present findings suggest that OXM and GLIC could, in that disease, contribute to exclude pathogens, due to their joined action on gut motility. [source] Undirected motility of filamentous cyanobacteria produces reticulate matsGEOBIOLOGY, Issue 3 2010R. N. SHEPARD The roles of biology in the morphogenesis of microbial mats and stromatolites remain enigmatic due to the vast array of physical and chemical influences on morphology. However, certain microbial behaviors produce complex morphological features that can be directly attributed to motility patterns. Specifically, laboratory experiments with a strain of the cyanobacteria Pseudanabaena demonstrate that distinctive morphologies arise from the undirected gliding and colliding of filaments. When filamentous cells collide, they align and clump, producing intersecting ridges surrounding areas with low cell density, i.e. reticulate structures. Cell motility is essential for the development of reticulates and associated structures: filaments organize into reticulates faster than cell division and growth, and conditions that inhibit motility also inhibit reticulate formation. Cell density of the inoculum affects the frequency of cell,cell collisions, and thus the time required for biofilm organization into reticulate structures. This also affects the specific geometry of the reticulates. These patterns are propagated into larger structures as cyanobacterial cell numbers increase and cells remain motile. Thus, cell motility is important for templating and maintaining the morphology of these microbial communities, demonstrating a direct link between a microbial behavior and a community morphology. Reticulate geometries have been identified in natural microbial mats as well as in the fossil record, and these structures can be attributed to the motility of filamentous bacteria. [source] Neural mechanisms of early postinflammatory dysmotility in rat small intestineNEUROGASTROENTEROLOGY & MOTILITY, Issue 12 2006I. Demedts Abstract, Although human postinflammatory dysmotility is known, so far animal studies have primarily investigated changes during inflammation. Here, we focused on postinflammatory changes in rat jejunal myenteric plexus and jejunal motility. Evolution of ethanol/2,4,6-tri-nitrobenzene sulphonic acid (TNBS)-induced inflammation was assessed histologically and by measuring myeloperoxidase activity (MPO). Electromyography and immunohistochemistry were performed 1 week after ethanol/TNBS and also after NG -nitro- l -arginine methyl ester (l -NAME) administration. Ethanol/TNBS induced a transient inflammation, with normalization of MPO and histological signs of an early phase of recovery after 1 week. The number of cholinergic neurones was not altered, but myenteric neuronal nitric oxide synthase (nNOS)-immunoreactivity was significantly lower in the early phase of recovery after TNBS compared with water (1.8 ± 0.2 vs 3.5 ± 0.2 neurones ganglion,1, P < 0.001). Interdigestive motility was disrupted with a loss of phase 1 quiescence, an increase of migrating myoelectric complex cycle length, a higher number of non-propagated activity fronts and a decrease of adequately propagated phase 3 s after TNBS. Administration of l -NAME resulted in a similar disruption of interdigestive motility patterns. In the early phase of recovery after ethanol/TNBS-induced jejunal inflammation, a loss of motor inhibition occurs due to a decrease of myenteric nNOS activity. These observations may provide a model for early postinflammatory dysmotility syndromes. [source] Fully automated analysis of colonic manometry recordingsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2002A. M. P. De Schryver AbstractThe purpose of this study was to develop a computer program for fully automated analysis of all presently known motor patterns in human colonic motility recordings. Colonic pressure recordings obtained from 24 healthy volunteers were used. Algorithms were developed for the detection and numerical analysis of five types of pressure waves: antegrade, retrograde, simultaneous, high-amplitude and isolated pressure waves. Furthermore, periodical motor activity was quantified. Validation was performed by comparison with visual analysis by two experienced observers. Patterns recorded during day- and night-time were compared using multiple-factor analysis of variance with Bonferroni correction. Automated analysis correlated well with visual peak detection (r = 0.98, P <0.01) and detection of antegrade pressure waves (r = 0.98, P <0.01). Most motor patterns showed a diurnal variation. During the night, prevalences of antegrade (938 vs 455; P <0.05), retrograde (112 vs 81; P <0.05), high-amplitude (12.9 vs 1.3; P <0.05), isolated pressure waves (1114 vs 765; P <0.05), and periodic motor activity were decreased (7.33 vs 4.47%; P <0.05). However, when expressed as percentage of absolute numbers of pressure waves, prevalences remained constant. In conclusion, fully automated analysis of all hitherto described colonic motility patterns is feasible. During the night, overall wave prevalences markedly decreased, but the distribution over the various motor patterns was preserved. [source] CASA Assessment of Kinematic Parameters of Ram Spermatozoa and their Relationship to Migration Efficiency in Ruminant Cervical MucusREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2008I Robayo Contents Sperm motility is an indicator of male fertility because of its importance for sperm migration through the female genital tract and for gamete interaction at fertilization. This study analyses the relationship between computer assisted semen analysis (CASA) motility patterns and sperm migration of rams in ruminant cervical mucus. In experiment 1, spermatozoa extended with sperm analysis medium (SAM) and seminal plasma were compared in terms of motility. In experiment 2, 56 semen samples were collected either with artificial vagina (AV) or electroejaculator to be compared in terms of motility performance. In experiment 3, 104 ejaculates collected by AV from 26 males were analysed via the CASA system to characterize their motility patterns. In experiment 4, ejaculates from pairs of rams (20 rams in total) were simultaneously assessed for mucus migration (ovine, caprine, bovine) and motility patterns to evaluate the correlations between both parameters. Semen collected by AV and extended in SAM allows the most reliable assessment for sperm motility. Ram spermatozoa move fast and follow a linear trajectory compared with other ruminants. Continuous line velocity (VCL) and average path velocity (VAP) are the only sperm kinematic parameters that presented significant positive correlations with the ability to migrate in sheep cervical mucus (p < 0.05). Continuous line velocity, VAP, straight line velocity and linearity are highly significantly related with migration efficiency in goat cervical mucus (p < 0.01) and only lateral head displacement is negatively related to sperm migration in bovine cervical mucus (p < 0.05). These results suggest that specific kinematic parameters confer the ability of spermatozoa to colonize and migrate through epithelial mucus with different rheological properties. [source] The first intestinal motility patterns in fetal mice are not mediated by neurons or interstitial cells of CajalTHE JOURNAL OF PHYSIOLOGY, Issue 7 2010Rachael R. Roberts In mature animals, neurons and interstitial cells of Cajal (ICC) are essential for organized intestinal motility. We investigated motility patterns, and the roles of neurons and myenteric ICC (ICC-MP), in the duodenum and colon of developing mice in vitro. Spatiotemporal mapping revealed regular contractions that propagated in both directions from embryonic day (E)13.5 in the duodenum and E14.5 in the colon. The propagating contractions, which we termed ripples, were unaffected by tetrodotoxin and were present in the intestine of embryonic Ret null mutant mice, which lack enteric neurons. Neurally mediated motility patterns were first observed in the duodenum at E18.5. To examine the possible role of ICC-MP, three approaches were used. First, intracellular recordings from the circular muscle of the duodenum did not detect slow wave activity at E16.5, but regular slow waves were observed in some preparations of E18.5 duodenum. Second, spatiotemporal mapping revealed ripples in the duodenum of E13.5 and E16.5 W/Wv embryos, which lack KIT+ ICC-MP and slow waves. Third, KIT-immunoreactive cells with the morphology of ICC-MP were first observed at E18.5. Hence, ripples do not appear to be mediated by ICC-MP and must be myogenic. Ripples in the duodenum and colon were abolished by cobalt chloride (1 mm). The L-type Ca2+ channel antagonist nicardipine (2.5 ,m) abolished ripples in the duodenum and reduced their frequency and size in the colon. Our findings demonstrate that prominent propagating contractions (ripples) are present in the duodenum and colon of fetal mice. Ripples are not mediated by neurons or ICC-MP, but entry of extracellular Ca2+ through L-type Ca2+ channels is essential. Thus, during development of the intestine, the first motor patterns to develop are myogenic. [source] | |||||||||||||