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Metabolic Components (metabolic + component)
Selected AbstractsThe metabolic component of cellular refractivity and its importance for optical cytometryJOURNAL OF BIOPHOTONICS, Issue 8-9 2009V. TychinskyArticle first published online: 30 JUL 200 Abstract Initially, it has been shown that the phase thickness and refractivity (the latter interpreted as the difference of the refractivity indices of an object and surrounding medium) depend on the functional state of mitochondria. The refractivity of various objects decreased in response to energy depletion. This dependence was then demonstrated for other biological objects such as cyanobacteria, chloroplasts and human cells. This general response brought about the hypothesis of a certain "universal" factor that links the variable (or metabolic) component of refractivity with the object's functional state. However, the origin of this phenomenon remains unknown. Our hypothesis is founded on the dependence of polarization of bound water molecules and the activity of metabolic processes. Here, we show the results of measurements of metabolic component of refractivity different bio-objects (mitochondria, chloroplasts, spores, cancer cells) obtained using the Coherent Phase Microscope "Airyscan". Estimations indicated high (up to n , 1.41,1.45) values for the equivalent refractive index of structured water in cells. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] From ancient genes to modern communities: the cellular stress response and the evolution of plant strategiesFUNCTIONAL ECOLOGY, Issue 5 2005S. PIERCE Summary 1Two major plant strategy theories attempt to explain how phenotype determines community structure. Crucially, CSR plant strategy theory suggests that stress and sporadic resource availability favour conservative phenotypes, whereas the resource-ratio hypothesis views the spatial heterogeneity of resources as selecting for optimal foraging in chronically unproductive habitats. Which view is most realistic? 2The ecophysiology literature demonstrates that stress is comprised of two processes: (1) limitation of resource supply to metabolism; and (2) damage to biomembranes, proteins and genetic material (chronic stress). Thus stress is defined mechanistically as the suboptimal performance of metabolism. 3Adaptations to limitation buffer metabolism against variability in external resource supply; internal storage pools are more consistent. Chronic stress elicits the same ancient cellular stress response in all cellular life: investment in stress metabolites that preserve the integrity and compartmentalization of metabolic components in concert with molecular damage-repair mechanisms. 4The cellular stress response was augmented by morphological innovations during the Silurian,Devonian terrestrial radiation, during which nutrient limitation appears to have been a principal selection pressure (sensu CSR theory). 5The modern stress,tolerator syndrome is conservative and supports metabolism in limiting or fluctuating environmental conditions: standing resource pools with high investment/maintenance costs impose high internal diffusion resistances and limit inherent growth rate (sensu CSR theory). 6The resource-ratio hypothesis cannot account for the cellular stress response or the crucial role of ombrotrophy in primary succession. CSR theory agrees with current understanding of the cellular stress response, terrestrial radiation and modern adaptations recorded in chronically unproductive habitats, and is applicable as CSR classification. [source] Heterogeneity of Ventricular Fibrillation Dominant Frequency During Global Ischemia in Isolated Rabbit HeartsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2007Ch.B. , JANE CALDWELL M.B. Introduction: Ventricular fibrillation (VF) studies show that ECG-dominant frequency (DF) decreases as ischemia develops. This study investigates the contribution of the principle ischemic metabolic components to this decline. Methods and Results: Rabbit hearts were Langendorff-perfused at 40 mL/min with Tyrode's solution and loaded with RH237. Epicardial optical action potentials were recorded with a photodiode array (256 sites, 15 × 15 mm). After 60 seconds of VF (induced by burst pacing), global ischemia was produced by low flow (6 mL/min), or the solution changed to impose hypoxia (95% N2/5% CO2), low pHo (6.7, 80% O2/20% CO2), or raised [K+]o (8 mM). DF of the optical signals was determined at each site. Conduction velocity (CV), action potential duration (APD90), effective refractory period (ERP), activation threshold, dV/dtmax, and membrane potential were measured in separate experiments during ventricular pacing. During VF, ischemia decreased DF in the left ventricle (LV) (to [58 ± 6]%, P < 0.001), but not the right (RV) ([93 ± 5]%). Raised [K+]o reproduced this DF pattern (LV: [67 ± 12]%, P < 0.001; RV: [95 ± 9]%). LV DF remained elevated in hypoxia or low pHo. During ventricular pacing, ischemia decreased CV in LV but not RV. Raised [K+]o did not change CV in either ventricle. Ischemia and raised [K+]o shortened APD90 without altering ERP. LV activation threshold increased in both ischemia and raised [K+]o and was associated with diastolic depolarization and decreased dV/dtmax. Conclusions: These results suggest that during VF, decreased ECG DF in global ischemia is largely due to elevated [K+]o affecting the activation thresholds in the LV rather than RV. [source] Association between metabolic syndrome and periodontal diseaseAUSTRALIAN DENTAL JOURNAL, Issue 3 2010OM Andriankaja Abstract Background:, Metabolic syndrome has been suggested as a potential risk factor for periodontal disease. Data based on NHANES III, with 7431 subjects aged 20 years or older, were analysed to confirm the association between metabolic syndrome and periodontal disease, and identify which components of metabolic syndrome might play a role in this association. Methods:, Clinical criteria for metabolic syndrome included: (1) abdominal obesity; (2) increased triglycerides; (3) decreased HDL cholesterol; (4) hypertension or current use of hypertension medication; and (5) high fasting plasma glucose. Periodontal disease was evaluated by probing pocket depth (PPD) and was defined as mean PPD ,2.5 mm. Results:, Women with two or more metabolic components had significantly increased odds of having periodontal disease as compared to those with no component [(two components, OR = 5.6 (95% CI: 2.2,14.4); three or more, OR = 4.7 (2.0,11.2)]. Using the definition of metabolic syndrome as having three to five metabolic components (reference group with <3 components), the adjusted odds ratios were 1.0 (0.7,1.6) for men and 2.1 (1.2,3.7) for women. Abdominal obesity was the largest contributory factor in both genders. Conclusions:, While the association between metabolic syndrome and periodontal disease was particularly significant for women, abdominal obesity appeared to be the contributing metabolic factor for both genders. [source] Analysis of chemical and metabolic components in traditional Chinese medicinal combined prescription containing Radix Salvia miltiorrhiza and Radix Panax notoginseng by LC-ESI-MS methodsBIOMEDICAL CHROMATOGRAPHY, Issue 8 2007Ying-Jie Wei Abstract High-performance liquid chromatography,electrospray ionization-mass spectrometry (LC-ESI-MS) methods were developed for the analysis of chemical and metabolic components in traditional Chinese medicinal combined prescription containing Radix Salvia miltiorrhiza and Radix Panax notoginseng (commonly known as Fufang Danshen prescription, FDP). The HPLC experiments used a reversed-phase Zorbax C18 column with the column temperature at 30°C and a binary mobile phase system consisting of aqueous formic acid (0.1%, v/v) and acetonitrile using a gradient elution at the flow rate of 1.0 mL/min. The ESI-MS was operated with a single-quadrupole mass spectrometer in both negative and positive ion modes. 36 major chromatographic peaks of FDP, including 14 saponins, 13 phenolic acids and nine diterpenoid quinones were characterized by their MS spectra and in comparison with some of the reference standards. In addition, after oral administration of extraction of FDP, the rat's plasma, urine and feces were also analyzed; 53 metabolic components including 30 original components and 23 transformative components of FDP were detected, and possible metabolic pathways of some components in FDP were given. The analysis of chemical and metabolic components in FDP by HPLC-MS methods could be a useful means of identifying the multi-components of FDP and to hint at their possible metabolic mechanism of action in the body. Copyright © 2007 John Wiley & Sons, Ltd. [source] Tapetoretinal degenerations: Experiences, experiments and expectationsACTA OPHTHALMOLOGICA, Issue 3 2000Berndt Ehinger ABSTRACT. Tapetoretinal degenerations are a common cause for vision problems, but have until recently not been amenable to rational treatment. With rapidly increasing insights into basic neurobiology and pathobiology this has now begun to change. From having been a relatively small group of largely unknown yet fairly prevalent disorders, they are rapidly forming a large set of well defined diseases, and it is easy to predict that our knowledge about them will continue to increase for many years to come. Vitamin A (15 ,000 IU daily) is currently the only rational treatment available. However, in experimental animals, therapy strategies are now actively being developed along several different lines. Apoptotic photoreceptor cell death can be delayed with different drugs, and at least one of them, diltiazem, is approved for human use in cardiovascular diseases. It remains to be seen if it has any clinically significant effect in human tapetoretinal degenerations. Other strategies aim at counteracting the production of harmful protein variants, acting either on DNA or mRNA levels. Transgenes can also be used to induce the production of important but missing metabolic components. Finally, cells or retina sheets can be transplanted, either to replace failing cells or as a source for missing trophic factors. Neither of these strategies has yet been transferred to humans, but trials are under way. With the high increase in the flow of new information on tapetoretinal disorders, much more precise diagnoses and much improved treatments are soon to be expected, augmenting considerably the possibilities for ophthalmologists to help patients with such diseases. It is not likely that there will be a single treatment for all the many varieties. Instead, we are most likely going to see pharmacological treatments for some of them, DNA transfers for some, and transplantations for others. [source] Inhibition of calcineurin increases monocarboxylate transporters 1 and 4 protein and glycolytic enzyme activities in rat soleus muscleCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2005Masataka Suwa SUMMARY 1.,The present study was designed to examine the role of calcineurin in muscle metabolic components by the administration of the specific calcineurin inhibitor cyclosporine A (CsA) to rats. 2.,Male Wistar rats were divided into either a CsA-treated group (CT) or a vehicle-treated group (VT). Cyclosporine A was administered subcutaneously to rats at a rate of 25 mg/kg bodyweight per day for 10 successive days. Thereafter, changes in muscle enzyme activities and glucose transporter (GLUT)-4 and monocarboxylate transporter (MCT)-1 and MCT-4 proteins in the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles were examined. 3.,There was a significant increase in MCT-1 and MCT-4 proteins in the soleus muscle in the CT group, but not in the EDL muscle. The activities of hexokinase, pyruvate kinase and lactate dehydrogenase in the soleus muscle also increased significantly in the CT group, but a similar increase in enzyme activity was not seen in EDL muscle. The activities of citrate synthase or malate dehydrogenase and the GLUT-4 protein content were not altered by CsA treatment in either the soleus or EDL muscles. 4.,These results seem to imply that calcineurin negatively regulates the components of glucose/lactate metabolism, except for GLUT-4, especially in slow-twitch muscle. [source] | ||||||||||