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Underlying Changes (underlying + change)
Selected AbstractsChronic Obstructive Pulmonary Disease Diagnosis and Management in Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2010Nalaka S. Gooneratne MD Chronic obstructive pulmonary disease (COPD) in older adults is a complex disorder with several unique age-related aspects. Underlying changes in pulmonary lung function and poor sensitivity to bronchoconstriction and hypoxia with advancing age can place older adults at greater risk of mortality or other complications from COPD. The establishment of the Global Initiative for Obstructive Lung Disease criteria, which can be effectively applied to older adults, has more rigorously defined the diagnosis and management of COPD. An important component of this approach is the use of spirometry for disease staging, a procedure that can be performed in most older adults. The management of COPD includes smoking cessation, influenza and pneumococcal vaccinations, and the use of short- and long-acting bronchodilators. Unlike with asthma, corticosteroid inhalers represent a third-line option for COPD. Combination therapy is frequently required. When using various inhaler designs, it is important to note that older adults, especially those with more-severe disease, may have inadequate inspiratory force for some dry-powder inhalers, although many older adults find the dry-powder inhalers easier to use than metered-dose inhalers. Other important treatment options include pulmonary rehabilitation, oxygen therapy, noninvasive positive airway pressure, and depression and osteopenia screening. Clinicians caring for older adults with an acute COPD exacerbation should also guard against prognostic pessimism. Although COPD is associated with significant disability, there is a growing range of treatment options to assist patients. [source] The periaqueductal grey modulates sensory input to the cerebellum: a role in coping behaviour?EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2009Nadia L. Cerminara Abstract The paths that link the periaqueductal grey (PAG) to hindbrain motor circuits underlying changes in behavioural responsiveness to external stimuli are unknown. A major candidate structure for mediating these effects is the cerebellum. The present experiments test this directly by monitoring changes in size of cerebellar responses evoked by peripheral stimuli following activation of the PAG. In 22 anaesthetized adult Wistar rats, climbing fibre field potentials were recorded from the C1 zone in the paramedian lobule and the copula pyramidis of the cerebellar cortex evoked, respectively, by electrical stimulation of the ipsilateral fore- and hindlimb. An initial and a late response were attributable to activation of A, and A, peripheral afferents respectively (hindlimb onset latencies 16.9 and 23.8 ms). Chemical stimulation at physiologically-identified sites in the ventrolateral PAG (a region known to be associated with hyporeactive immobility) resulted in a significant reduction in size of both the A, and A, evoked field potentials (mean reduction relative to control ± SEM, 59 ± 7.5 and 66 ± 11.9% respectively). Responses evoked by electrical stimulation of the dorsal or ventral funiculus of the spinal cord were also reduced by PAG stimulation, suggesting that part of the modulation may occur at supraspinal sites (including at the level of the inferior olive). Overall, the results provide novel evidence of descending control into motor control centres, and provide the basis for future studies into the role of the PAG in regulating motor activity in different behavioural states and in chronic pain. [source] Dynamic macroecology on ecological time-scalesGLOBAL ECOLOGY, Issue 1 2010Jonathan A. D. Fisher ABSTRACT Aim, The discipline of macroecology is increasingly being regarded as an effective vehicle for the evaluation of recent population- to ecosystem-level responses to widespread human and environmental influences. However, due to the prevalent use of time-averaged and cumulative data in macroecological analyses, the majority of the patterns that emerge from research in this field can be regarded as static. Here we review the application of dynamic macroecological analyses to changes in relationships between macroecological variables on seasonal to decadal scales. We illustrate the strength of this perspective for documenting changing patterns and testing hypotheses related to these dynamics on ecological time-scales. Location, Studies were compiled and reviewed from terrestrial and aquatic ecosystems. Methods, We review examples of temporal changes in macroecological patterns driven by recent anthropogenic influences and environmental change. Results, The dynamic nature of macroecological patterns on ecological time-scales has been revealed in recent years across a wide range of ecosystems, largely through the development, maintenance and analysis of biotic and environmental monitoring time series. The resultant analyses complement examinations of dynamics over evolutionary time and have similarly revealed that static portrayals can conceal important temporal dynamics that underlie the patterns of interest. As a consequence, static depictions, resting as they do on comparative analyses in which the validity of space-for-time substitutions is assumed, may be of limited use for testing hypotheses related to the mechanisms underlying the patterns revealed and, by extension, the development of reliable predictions of future states. Main conclusions, Recent dynamic macroecological analyses have demonstrated the utility of combined spatial and temporal replication, and have contributed to hypothesis testing related to the mechanistic processes underlying changes in macroecological patterns on ecological time-scales. We suggest four specific avenues of future research to further the development and application of temporal approaches on similar time-scales within the field of macroecology. [source] Regionalism: Old and NewINTERNATIONAL STUDIES REVIEW, Issue 1 2003Raimo Väyrynen This review of recent literature on political, economic, and cultural regionalism shows that this area of inquiry has become increasingly fragmented not only as a result of debates between the protagonists of methodological approaches but also because of underlying changes in international relations. Traditional views concerning the state-centric regional system are being challenged by the concentration of political and military power at the top as well as by transnational networks built around economic ties and cultural identities. Early post-Cold War expectations that regions and regional concerts would form the foundation for a new international order have proven untenable. Instead, regions appear to arise either through the dissemination of various transactions and externalities or as protection against the hegemony of capitalist globalization and great-power politics. Older conceptions of regionalism need to be redefined and reintegrated into current international relations theories. [source] Testosterone, growth and the evolution of sexual size dimorphismJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2009R. M. COX Abstract The integration of macroevolutionary pattern with developmental mechanism presents an outstanding challenge for studies of phenotypic evolution. Here, we use a combination of experimental and comparative data to test whether evolutionary shifts in the direction of sexual size dimorphism (SSD) correspond to underlying changes in the endocrine regulation of growth. First, we combine captive breeding studies with mark-recapture data to show that male-biased SSD develops in the brown anole lizard (Anolis sagrei) because males grow significantly faster than females as juveniles and adults. We then use castration surgeries and testosterone implants to show that castration inhibits, and testosterone stimulates, male growth. We conclude by reviewing published testosterone manipulations in other squamate reptiles in the context of evolutionary patterns in SSD. Collectively, these studies reveal that the evolution of SSD has been accompanied by underlying changes in the effect of testosterone on male growth, potentially facilitating the rapid evolution of SSD. [source] Changes in patients' need of nursing care reflected in the Zebra systemJOURNAL OF NURSING MANAGEMENT, Issue 4 2002A.-K. Levenstam RN, MSc (business administration) During 1995,97, many head nurses stated that they had perceived an increase in patients' need of nursing care. A questionnaire was designed to determine the reasons for this. The purpose of the investigation was to answer two questions, ,What were the reasons for head nurses perception of an increase in patients need of nursing care from 1995 to May 1997?' and, ,Does patient classification in the Zebra system reflect the underlying changes in patients' need of nursing care? The results show that there are several reasons behind changes in the patients need of nursing care. The main reasons are a decreased general level of health among patients and that treatments are more time-consuming. After comparing statistics concerning patient classification with the answers received from the questionnaire, a good level of agreement could be seen in these. [source] Differential Adaptations in GABAergic and Glutamatergic Systems During Ethanol Withdrawal in Male and Female RatsALCOHOLISM, Issue 6 2005P E. Alele Background: There are significant and consistent sex differences in recovery from ethanol withdrawal in our animal model of ethanol dependence. We have also observed significant and varied sex differences in subunit protein levels of ,-aminobutyric acid A (GABAA) and the N-metheyl-D-aspartate subtype of glutamate receptors occurring with ethanol dependence and withdrawal. Considering the major role of these two systems as targets of ethanol, we wanted to explore additional possible mechanisms underlying changes in GABAergic and glutamatergic responses after chronic ethanol exposure. Therefore, the objective of the present study was to examine GABAergic- and glutamatergic-associated proteins at three days of ethanol withdrawal, when female rats appear to have largely recovered but male rats still display robust signs of withdrawal. Methods: Male and female rats were fed 6% ethanol in a nutritionally complete liquid diet for 14 days according to a pair-fed design; withdrawal was initiated by replacement of the diet with chow. At three days of withdrawal, the cerebral cortex and hippocampus were dissected for use in Western blot analysis. The paired design was maintained throughout all experimental procedures. Results: At three days of ethanol withdrawal, we found region-specific and sex-selective alterations in levels of GAD (glutamic acid decarboxylase, GABA synthetic enzyme), GABA and glutamate transporters, and the synapse-associated proteins HSP70, PSD-95, and synaptophysin. There were also several significant differences in transporter function at this time that varied between males and females. Conclusions: Taken together, these findings show differential adaptations of GABAergic and glutamatergic neurotransmission between female and male rats that are associated with withdrawal recovery. This suggests that selective withdrawal-induced neuroadaptations in regulation of these systems' activities underlie, at least in part, sex differences in withdrawal recovery between male and female rats. [source] Lung function tests in neonates and infants with chronic lung disease: Lung and chest-wall mechanicsPEDIATRIC PULMONOLOGY, Issue 4 2006Monika Gappa MD This is the fifth paper in a review series that summarizes available data and critically discusses the potential role of lung function testing in infants and young children with acute neonatal respiratory disorders and chronic lung disease of infancy (CLDI). This review focuses on respiratory mechanics, including chest-wall and tissue mechanics, obtained in the intensive care setting and in infants during unassisted breathing. Following orientation of the reader to the subject area, we focused comments on areas of enquiry proposed in the introductory paper to this series. The quality of the published literature is reviewed critically with respect to relevant methods, equipment and study design, limitations and strengths of different techniques, and availability and appropriateness of reference data. Recommendations to guide future investigations in this field are provided. Numerous different methods have been used to assess respiratory mechanics with the aims of describing pulmonary status in preterm infants and assessing the effect of therapeutic interventions such as surfactant treatment, antenatal or postnatal steroids, or bronchodilator treatment. Interpretation of many of these studies is limited because lung volume was not measured simultaneously. In addition, populations are not comparable, and the number of infants studied has generally been small. Nevertheless, results appear to support the pathophysiological concept that immaturity of the lung leads to impaired lung function, which may improve with growth and development, irrespective of the diagnosis of chronic lung disease. To fully understand the impact of immaturity on the developing lung, it is unlikely that a single parameter such as respiratory compliance or resistance will accurately describe underlying changes. Assessment of respiratory mechanics will have to be supplemented by assessment of lung volume and airway function. New methods such as the low-frequency forced oscillation technique, which differentiate the tissue and airway components of respiratory mechanics, are likely to require further development before they can be of clinical significance. Pediatr Pulmonol. © 2006 Wiley-Liss, Inc. [source] Blunting of rapid onset vasodilatation and blood flow restriction in arterioles of exercising skeletal muscle with ageing in male miceTHE JOURNAL OF PHYSIOLOGY, Issue 12 2010Dwayne N. Jackson Exercise capacity and skeletal muscle blood flow are diminished with ageing but little is known of underlying changes in microvascular haemodynamics. Further, it is not clear how the sympathetic nervous system affects the microcirculation of skeletal muscle with ageing or whether sex differences prevail in the regulation of arteriolar diameter in response to muscle contractions. In the gluteus maximus muscle of C57BL/6 mice, we tested the hypothesis that ageing would impair ,rapid onset vasodilatation' (ROV) in distributing arterioles (second-order, 2A) of old (20-month) males (OM) and females (OF) relative to young (3-month) males (YM) and females (YF). Neither resting (,17 ,m) nor maximum (,30 ,m) 2A diameters differed between groups. In response to single tetanic contractions at 100 Hz (duration, 100,1000 ms), ROV responses were blunted by half in OM relative to OF, YM or YF. With no effect in YM, blockade of ,-adrenoreceptors with phentolamine (1 ,m) restored ROV in OM. Topical noradrenaline (1 nm) blunted ROV in YM and YF to levels seen in OM and further suppressed ROV in OM (P < 0.05). To evaluate arteriolar blood flow, red blood cell velocity was measured in 2A of OM and YM; respective heart rates (353 ± 22 vs. 378 ± 15 beats min,1) and carotid arterial blood pressures (76 ± 3 vs. 76 ± 1 mmHg) were not different. Blood flows at rest (0.6 ± 0.1 vs. 1.6 ± 0.2 nl s,1) and during maximum dilatation (2.0 ± 0.8 vs. 5.4 ± 0.8 nl s,1) with sodium nitroprusside (10 ,m) were attenuated >60% (P < 0.05) in OM. Blood flow at peak ROV was blunted by 75,80% in OM vs. YM (P < 0.05). In response to 30 s of rhythmic contractions at 2, 4 and 8 Hz, progressive dilatations did not differ with age or sex. Nevertheless, resting and peak blood flows in YM were 2- to 3-fold greater (P < 0.05) than OM. We suggest that ageing blunts ROV and restricts blood flow to skeletal muscle of OM through subtle activation of ,-adrenoreceptors in microvascular resistance networks. [source] SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomatoTHE PLANT JOURNAL, Issue 2 2010Jonathan T. Vogel Summary The regulation of shoot branching is an essential determinant of plant architecture, integrating multiple external and internal signals. One of the signaling pathways regulating branching involves the MAX (more axillary branches) genes. Two of the genes within this pathway, MAX3/CCD7 and MAX4/CCD8, encode carotenoid cleavage enzymes involved in generating a branch-inhibiting hormone, recently identified as strigolactone. Here, we report the cloning of SlCCD7 from tomato. As in other species, SlCCD7 encodes an enzyme capable of cleaving cyclic and acyclic carotenoids. However, the SlCCD7 protein has 30 additional amino acids of unknown function at its C terminus. Tomato plants expressing a SlCCD7 antisense construct display greatly increased branching. To reveal the underlying changes of this strong physiological phenotype, a metabolomic screen was conducted. With the exception of a reduction of stem amino acid content in the transgenic lines, no major changes were observed. In contrast, targeted analysis of the same plants revealed significantly decreased levels of strigolactone. There were no significant changes in root carotenoids, indicating that relatively little substrate is required to produce the bioactive strigolactones. The germination rate of Orobanche ramosa seeds was reduced by up to 90% on application of extract from the SlCCD7 antisense lines, compared with the wild type. Additionally, upon mycorrhizal colonization, C13 cyclohexenone and C14 mycorradicin apocarotenoid levels were greatly reduced in the roots of the antisense lines, implicating SlCCD7 in their biosynthesis. This work demonstrates the diverse roles of MAX3/CCD7 in strigolactone production, shoot branching, source,sink interactions and production of arbuscular mycorrhiza-induced apocarotenoids. [source] Profiling of N -glycosylation gene expression in CHO cell fed-batch culturesBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010Danny Chee Furng Wong Abstract One of the goals of recombinant glycoprotein production is to achieve consistent glycosylation. Although many studies have examined the changes in the glycosylation quality of recombinant protein with culture, very little has been done to examine the underlying changes in glycosylation gene expression as a culture progresses. In this study, the expression of 24 genes involved in N -glycosylation were examined using quantitative RT PCR to gain a better understanding of recombinant glycoprotein glycosylation during production processes. Profiling of the N -glycosylation genes as well as concurrent analysis of glycoprotein quality was performed across the exponential, stationary and death phases of a fed-batch culture of a CHO cell line producing recombinant human interferon-, (IFN-,). Of the 24 N -glycosylation genes examined, 21 showed significant up- or down-regulation of gene expression as the fed-batch culture progressed from exponential, stationary and death phase. As the fed-batch culture progressed, there was also an increase in less sialylated IFN-, glycoforms, leading to a 30% decrease in the molar ratio of sialic acid to recombinant IFN-,. This correlated with decreased expression of genes involved with CMP sialic acid synthesis coupled with increased expression of sialidases. Compared to batch culture, a low glutamine fed-batch strategy appears to need a 0.5,mM glutamine threshold to maintain similar N -glycosylation genes expression levels and to achieve comparable glycoprotein quality. This study demonstrates the use of quantitative real time PCR method to identify possible "bottlenecks" or "compromised" pathways in N -glycosylation and subsequently allow for the development of strategies to improve glycosylation quality. Biotechnol. Bioeng. 2010;107: 516,528. © 2010 Wiley Periodicals, Inc. [source] Fluorophores as Optical Sensors for Local Forces,CHEMPHYSCHEM, Issue 12 2009Stefan Marawske Abstract The main aim of this study is to investigate correlations between the impact of an external mechanical force on the molecular framework of fluorophores and the resultant changes in their fluorescence properties. Taking into account previous theoretical studies, we designed a suitable custom-tailored oligoparaphenylenevinylene derivative (OPV5) with a twisted molecular backbone. Thin foils made of PVC doped with 100 nM OPV were prepared. By applying uniaxial force, the foils were stretched and three major optical effects were observed simultaneously. First, the fluorescence anisotropy increased, which indicates a reorientation of the fluorophores within the matrix. Second, the fluorescence lifetime decreased by approximately 2.5,% (25 ps). Finally, we observed an increase in the emission energy of about 0.2,% (corresponding to a blue-shift of 1.2 nm). In addition, analogous measurements with Rhodamine 123 as an inert reference dye showed only minor effects, which can be attributed to matrix effects due to refractive index changes. To relate the observed spectroscopic changes to the underlying changes in molecular properties, quantum-chemical calculations were also performed. Semiempirical methods had to be used because of the size of the OPV5 chromophore. Two conformers of OPV5 (C2 and Cisymmetry) were considered and both gave very similar results. Both the observed blue-shift of fluorescence and the reduced lifetime of OPV5 under tensile stress are consistent with the results of the semiempirical calculations. Our study proves the feasibility of fluorescence-based local force probes for polymers under tension. Improved optical sensors of this type should in principle be able to monitor local mechanical stress in transparent samples down to the single-molecule level, which harbors promising applications in polymer science and nanotechnology. [source] | |||||||||||||