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Active Stage (active + stage)
Selected AbstractsActive Vegetations Can Be Differentiated from Chronic Vegetations by Visual Inspection of Standardized Two-Dimensional EchocardiogramsECHOCARDIOGRAPHY, Issue 2 2000PH.D., TAHIR TAK M.D. The ability to differentiate active from chronic valvular vegetations (VEGs) by digital image processing and by visual observation was evaluated in 18 patients with a clinical diagnosis of infective endocarditis (IE). Two-dimensional echocardiographic (2-DE) examinations were performed on all patients at diagnosis and after a mean period of 52 days. Two comparable images (active and chronic) from the same patient and in the same phase of the cardiac cycle were digitized, magnified, and displayed on a high resolution monitor. The mean pixel intensity (MPI) was 72 ± 14 in the active stage and 143 ± 23 in the chronic stage (P < 0.0001). The VEG size was 0.64 ± 0.15 cm2 in the active stage and decreased to 0.46 ± 0.17 cm2 in the chronic stage (P < 0.001). Two experienced echocar-diographers, who were blinded to the age of the VEGs, identified each echocardiographic image as active or chronic based on visual observation of density of the VEGs. The VEGs were correctly identified as active or chronic in 17 out of the 18 patients. In summary, although digital image processing of 2-DE may be useful, the density of VEGs assessed by visual inspection will help differentiate between active and chronic VEGs of IE. The standardization procedure at the time of the initial study and use of identical gain settings in subsequent studies are key factors in making this distinction. [source] Visual Function in Infants with West Syndrome: Correlation with EEG PatternsEPILEPSIA, Issue 7 2004Teresa Randò Summary:,Purpose: Several studies have reported behavioral and electrophysiological evidence of visual impairment during the active stage of West syndrome. The underlying mechanisms are, however, poorly understood, and little has been reported about the correlation between visual impairment, EEG patterns, and brain lesions. The aim of the study was to assess visual function at the onset of spasm and 2 months thereafter and relate visual findings to brain lesions and EEG features. Methods: Twenty-five infants with West syndrome were enrolled and studied with (a) a full clinical assessment including a battery of tests specifically designed to assess visual function, (b) a video-polygraphic study, and (c) brain magnetic resonance imaging (MRI). Besides brain neuroimaging and EEG comparison with visual function, an intra-EEG analysis was performed to investigate the possible relation of EEG patterns to fluctuating visual behavior (fixation and following). Results: Twenty-two children had at least one abnormal result on one or more of the tests assessing visual function at T0. Visual impairment at the spasm onset was related to the sleep disorganization rather than to the hypsarrhythmic pattern in awake EEG. After 2 months, both EEG features become significantly linked to visual function. Visual function improved in several cases after 2 months, in parallel with the seizure regression. No relation was found between EEG patterns and fluctuating visual behavior. Conclusions: The study supplies new evidence of the involvement of visual function in West syndrome. The presence of abnormal visual findings in infants without lesions on brain MRI suggests that visual abnormalities are due not only to brain injury but also to epileptic disorder per se. New insight is also provided into the possible mechanisms underlying clinical and EEG abnormalities. [source] Hatching fraction and timing of resting stage production in seasonal environments: effects of density dependence and uncertain season lengthJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2001M. Spencer Many organisms survive unfavourable seasons as resting stages, some of which hatch each favourable season. Hatching fraction and timing of resting stage production are important life history variables. We model life cycles of freshwater invertebrates in temporary pools, with various combinations of uncertain season length and density-dependent fecundity. In deterministic density-independent conditions, resting stage production begins suddenly. With uncertain season length and density independence, resting stage production begins earlier and gradually. A high energetic cost of resting stages favours later resting stage production and a lower hatching fraction. Deterministic environments with density dependence allow sets of coexisting strategies, dominated by pairs, each switching suddenly to resting stage production on a different date, usually earlier than without density dependence. Uncertain season length and density dependence allow a single evolutionarily stable strategy, around which we observe many mixed strategies with negatively associated yield (resting stages per initial active stage) and optimal hatching fraction. [source] Interleukin-6 and granulocyte-macrophage colony-stimulating factor in apical periodontitis: correlation with clinical and histologic findings of the involved teethMOLECULAR ORAL MICROBIOLOGY, Issue 1 2003T. Radics Apical periodontitis is characterized by the presence of immunocompetent cells producing a wide variety of inflammatory mediators. Releasing cytokines with long-range action, such as interleukin-6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM-CSF), apical periodontitis may induce changes in remote organs of the host. This study quantified the levels of IL-6 and GM-CSF in symptomatic and asymptomatic human periradicular lesions. Lesions were also characterized by size and histologic findings. Tissue samples were homogenized and supernatants were assayed using an enzyme-linked immunosorbent assay (ELISA). Correlations between cytokine levels and characteristic features (as single variables) of the lesions were analysed. There was a trend for higher levels of IL-6 and GM-CSF in symptomatic than in asymptomatic lesions, but the difference was not significant. Levels also tended to be higher in large than in small lesions, in polymorphonuclear (PMN) cell-rich than in PMN cell-poor samples, and in epithelialized than in non-epithelialized lesions. Significantly higher levels of IL-6 (778.1 ± 220.5 pg/,g) and GM-CSF (363.3 ± 98.4 pg/,g) were found in samples coincidentally possessing symptomatic and epithelialized features than in asymptomatic, small, PMN cell-poor, non-epithelialized lesions (IL-6: 45.2 ± 13.1 pg/,g and GM-CSF: 135.1 ± 26.4 pg/,g). These results suggest that symptomatic lesions containing epithelial cells represent an immunologically active stage of apical periodontitis, whereas asymptomatic, small, PMN cell-poor, non-epithelialized lesions represent healing apical lesions. [source] Transcriptome analysis of bud burst in sessile oak (Quercus petraea)NEW PHYTOLOGIST, Issue 4 2006Jérémy Derory Summary ,,Expression patterns of hundreds of transcripts in apical buds were monitored during bud flushing in sessile oak (Quercus petraea), in order to identify genes differentially expressed between the quiescent and active stage of bud development. ,,Different transcriptomic techniques combining the construction of suppression subtractive hybridization (SSH) libraries and the monitoring of gene expression using macroarray and real-time reverse transcriptase polymerase chain reaction (RT-PCR) were performed to dissect bud burst, with a special emphasis on the onset of the process. ,,We generated 801 expressed sequence tags (ESTs) derived from six developmental stages of bud burst. Macroarray experiment revealed a total of 233 unique transcripts exhibiting differential expression during the process, and a putative function was assigned to 65% of them. Cell rescue/defense-, metabolism-, protein synthesis-, cell cycle- and transcription-related transcripts were among the most regulated genes. Macroarray and real-time RT-PCR showed that several genes exhibited contrasted expressions between quiescent and swelling buds, such as a putative homologue of the transcription factor DAG2 (Dof Affecting Germination 2), previously reported to be involved in the control of seed germination in Arabidopsis thaliana. ,,These differentially expressed genes constitute relevant candidates for signaling pathway of bud burst in trees. [source] Multi-scale analysis of the 25,27 July 2006 convective period over Niamey: Comparison between Doppler radar observations and simulationsTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue S1 2010Christelle Barthe Abstract The present study investigates the multi-scale processes associated with a sequence of convective events that occurred over Niamey during the period 25,26 July 2006. This period corresponds to the active stage of the first intense monsoon surge over Sahel for 2006. During this two-day period, two successive sequences of mesoscale convective systems (MCSs) were located ahead of and in phase with the trough of an African Easterly Wave (AEW). They were followed by suppressed or isolated convection behind the trough and in the vicinity of the ridge. The large AMMA-SOP dataset, in particular the UHF radar and the MIT Doppler radar in Niamey, are used in combination with a low-resolution (5 km) cloud-resolving model to understand the convection organization and its interaction with the environment. Several initial and boundary conditions have been tested, but only the simulation starting with the ECMWF AMMA reanalysis succeeds in reproducing the observed features; this emphasizes the importance of the initial state. From the simulated MCSs, the along-line component of the apparent source of momentum due to the convection is found to be up to 1 m s,1h,1. It seems that MCSs globally reduce the monsoon flow and generate southerlies at mid levels which can reinforce the rotation of the wind at the passage of the trough. During the afternoon of 26 July, the local convection over Niamey resulted from some favourable factors (humidity, CAPE, CIN) that triggered convection, while inhibiting factors (mid-level dry layer, weaker low-level wind shear pointing to the north, anticyclonic curvature of the streamlines at 700 hPa) prevented it organizing itself and propagating. In particular, the low-level wind shear seems of critical importance. Copyright © 2010 Royal Meteorological Society [source] High remnant lipoprotein levels in patients with variant anginaCLINICAL CARDIOLOGY, Issue 6 2004Kunihisa Miwa M.D. Doctor-in-Chief Abstract Background: Dyslipidemia with increased oxidative stress but without elevation of low-density lipoprotein cholesterol has been recently implicated in the pathogenesis of coronary vasospasm. Hypothesis: Disordered triglyceride-rich lipoprotein metabolism may be linked to the genesis of coronary artery spasm. Methods: Both serum remnant lipoprotein (RLP) and ,-tocopherol levels were determined in 18 patients with the active stage of variant angina (VA), in 16 patients with the inactive stage of variant angina (IVA), and in 19 control subjects (CONTROL). Results: The RLP levels were significantly (p < 0.05) higher in VA (6.4 ± 2.7 mg/dl) than in IVA (4.4 ± 1.5 mg/dl). In contrast, ,-tocopherol levels were significantly lower in VA than that in CONTROL. Serum trigyceride levels were not significantly different among the study groups, although serum high-density lipoprotein cholesterol levels were significantly lower in VA than in CONTROL. Smoking was significantly (p < 0.05) more prevalent in VA (72%) than in IVA (25%) and CONTROL (37%). Serum RLP levels correlated positively with triglyceride levels (R = 0.73) and correlated inversely with ,-tocopherol levels (R = - 0.31) significantly in all study subjects. Conclusions: Patients with active stage of variant angina had higher RLP levels than inactive patients with variant angina and lower ,-tocopherol levels than control subjects. Disordered triglyceride-rich lipoprotein metabolism with increased oxidative stress appears to be linked to the activity of coronary vasospasm, suggesting a possible role in its pathogenesis. [source] Cold tolerance in obligate and cyclical parthenogens of the peach-potato aphid, Myzus persicaeECOLOGICAL ENTOMOLOGY, Issue 4 2004Christoph Vorburger Abstract., 1. Many aphids form mixed populations of cyclical and obligate parthenogens. This is puzzling, because all else being equal, obligate parthenogens should outcompete cyclical parthenogens due to the two-fold cost of sex. Yet cyclical parthenogens produce frost-resistant, diapausing eggs in autumn, while obligate parthenogens spend the winter as active stages. Frost resistance thus represents a short-term advantage to sexual reproduction mediated by winter temperatures, which may promote this coexistence. 2. Because obligate parthenogens overwinter as active stages, there may be selection for increased cold tolerance compared to cyclical parthenogens. This has the potential to gradually erode the advantage of sexually producing eggs. 3. Four obligately and four cyclically parthenogenetic lines of Myzus persicae (Sulzer) (Hemiptera: Aphididae) were collected from each of two areas differing in winter severity, and their survival after exposure to a severe experimental frost (14 h at ,9 °C), as well as their reproductive performance at a low (10 °C) and a high (20 °C) temperature were compared. 4. There was significant variation among lines in survival after the experimental frost, but this variation was neither related to their reproductive mode, nor to their area of origin. Similarly, neither reproductive mode nor origin had a significant effect on reproductive performance, independent of temperature. The average slope of the response to variation in temperature was also similar for both reproductive modes, despite the fact that slopes differed significantly among lines. 5. Within the limits of extrapolating from laboratory experiments, it is concluded that in M. persicae, the active stages of obligate parthenogens are not better adapted to cold temperatures than those of cyclical parthenogens. [source] | |||||||||||||