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Irreversible Damage (irreversible + damage)
Selected AbstractsOrofacial injury in a Brazilian professional basketball player: case reportDENTAL TRAUMATOLOGY, Issue 3 2006Ana Paula Pires Dos Santos Abstract,,, The frequency of dental trauma has increased among children and athletes of all ages who play contact sports. This kind of trauma may result in irreversible damage to the patient. The aim of this report is to present a case of an orofacial trauma involving a professional basketball player who was elbowed by another player. The athlete reported loss of sensitivity in three teeth and computerized tomography showed fractures in three points of the malar bone. After the incident and dental follow-up, the player was made aware of the need to wear a mouthguard. [source] Assessment of Incidence, Cause, and Consequences of Pressure Ulcers to Evaluate Quality of Provided CareDERMATOLOGIC SURGERY, Issue 11 2009JAN WILLEM H. P. LARDENOYE MD BACKGROUND Pressure ulcers are one of the most frequently registered complications in general surgery. OBJECTIVE To obtain insight into the incidence, cause, and consequences of pressure ulcers and to evaluate the value of pressure ulcer registration to assess quality of care. RESULTS During the 9-year study period, 275 pressure ulcers were registered (5.8% of total registered complications). Age and female sex were independent risk factors for pressure ulcer development. Pressure ulcer classification was as follows: mild (53.3%), moderate (35.6%), severe (9.5%), and irreversible damage (1.5%). Patients undergoing hip surgery and major limb amputation were at risk for pressure ulcer development (10.4% and 8.8%, respectively). In most patients (89.5%), pressure ulcers had no consequences other than local wound therapy; in 12 patients (4.4%), pressure ulceration led to alteration in medication; in 15 patients (5.5%), length of hospital stay was prolonged; and four patients (0.4%) suffered from irreversible damage. CONCLUSION The incidence of pressure ulcers is strongly correlated to sex, age, and indication of admittance. Most ulcers were classified as mild and had no consequences. The insight obtained into incidence, cause, and consequences of pressure ulcers can be used as an indicator of quality of provided care if adjusted for case mix and indication of operation. [source] Uptake and diverse effects of polycyclic aromatic hydrocarbons on the metabolic activity of Elliptio complanata measured by calorespirometryENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Marcos A. Cheney Abstract Polycyclic aromatic hydrocarbons (PAHs) are important contaminants of world water resources, with effects on aquatic life. Metabolic responses to short-term acute toxicities of naphthalene, anthracene, and chrysene were investigated in the freshwater bivalve mollusk Elliptio complanata using differential scanning calorespirometry coupled with uptake and scanning electron microscopy. Comparing the uptakes of naphthalene, anthracene, and chrysene with that of inulin, which is known to occupy only extracellular space, showed that all compounds studied were taken up. The PAHs studied had diverse effects on the metabolic activity of E. complanata. Naphthalene and, to a lesser degree, chrysene caused stimulation of heat rates, possibly due to uncoupling of oxidative metabolism. Differential scanning calorespirometry coupled with studies of rates of oxygen consumption by the gill tissue exposed to the PAHs showed similar diverse patterns of respiratory rate stimulation and inhibition. Analysis of results of scanning electron microscopy suggested that irreversible damage to the gill tissue occurred in the presence of anthracene but not in the presence on naphthalene or chrysene. The batch calorespirometric method coupled with uptake and spectroscopy proved to be a useful technique to assess the toxicity of PAHs on the control of energy flux in gills of a freshwater bivalve mollusk. [source] Chronological and replicative lifespan of polyploid Saccharomyces cerevisiae (syn. S. pastorianus)FEMS YEAST RESEARCH, Issue 2 2003Dawn L Maskell Abstract Chronological lifespan may be defined as the result of accumulation of irreversible damage to intracellular components during extended stationary phase, compromising cellular integrity and leading to death and autolysis. In contrast, replicative lifespan relates to the number of divisions an individual cell has undertaken before entering a non-replicative state termed senescence, leading to cell death and autolysis. Both forms of lifespan have been considered to represent models of ageing in higher eukaryotes, yet the relation between chronologically and replicatively aged populations has not been investigated. In this study both forms of lifespan have been investigated in Saccharomyces cerevisiae (Syn. S. pastorianus) to establish the relationship between chronological and replicative ageing. [source] Significance of determining the point of reperfusion failure in experimental torsion of testisINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005ELIJAH O KEHINDE Abstract Background:, Experimental studies of the use of free radical scavengers in ischemic/reperfusion (I/R) injury following detorsion of the torted testis have yielded conflicting results due to differences in the period of ischemia used. The authors studied I/R injury in the rabbit model, to define the point beyond which there is reperfusion failure. Methods:, Ischemia/reperfusion injury of the testis was created in 3,6-month-old male New Zealand white rabbits by cross-clamping the left spermatic cord for periods of ischemia lasting 0, 15, 30, 60, 90, 120 and 180 min. There were eight animals per experimental group. The right testis served as internal control. Both testes were harvested after 24 h of reperfusion in four animals and after 3 months in the remaining four animals for each group. Testicular malondialdehyde (MDA), a measure of free radical damage, was determined by using the thiobarbituric acid reaction on testicular homogenates. Johnsen score was used to assess morphological damage caused by the ischemia. Results:, After 24 h of reperfusion, the mean testicular MDA in the control right testes at 0, 15, 30, 60, 90, 120 and 180 min was 2.1, 2.5, 2.9, 2.4, 2.1 and 1.9 nmol/mg protein, respectively. The mean left testicular MDA at corresponding ischemic periods was 1.6, 2.0, 3.9, 10.0, 4.4, 6.1 and 1.0 nmol/mg protein, respectively. The maximum left testicular MDA was at 60 min (10.0 nmol/mg protein), following which the level dropped significantly to 1.0 nmol/mg protein at 180 min. At 3 months, the mean Johnsen scores for left testes subjected to 0, 60, 120 and 180 min ischemia were 9.4, 8.8, 2.3, 3.5, respectively. Conclusion:, The results suggest that following ischemia of up to 60 min in the rabbit testis, adequate reperfusion is possible, but ischemia lasting beyond 60 min results in inadequate reperfusion leading to irreversible damage. Thus, in experiments for assessing the effect of antioxidants on I/R injury of the testis in rabbits, periods up to 60 min of ischemia should be regarded as optimum to observe an effect. [source] Twenty-Four Hours Postoperative Results After Orthotopic Cardiac Transplantation in SwineJOURNAL OF CARDIAC SURGERY, Issue 4 2007Matthias Siepe M.D. However, there is no functional data available for a longer time period after transplantation. We have established a pig model to investigate myocardial function 24 hours after orthotopic transplantation.Materials and Methods: Orthotopic cardiac transplantations (HTx) in pigs were performed with a postoperative observation period of 24 hours (n = 6). To analyze myocardial function after transplantation, hemodynamical parameters (Swan-Ganz- and impedance-catheter data) as well as tissue and blood samples were obtained. Regional myocardial blood flow (RMBF) was assessed using fluorescent microspheres. Results: The impedance-catheter parameters demonstrated a preserved contractility in both ventricles 24 hours post-transplantation. In contrast, cardiac output 24 hours after HTx was diminished by 50% as compared to the preoperative value. Conversely, pulmonary vascular resistance increased significantly. The RMBF was increased in both ventricles. Metabolic and histological analyses indicate myocardial recovery 24 hours after HTx with no irreversible damage. Conclusions: For the first time, we were able to establish a porcine model to investigate myocardial function 24 hours after heart transplantation. While the contractility of the transplanted hearts was well-preserved, impaired cardiac output was going along with an increase in pulmonary vascular resistance. Using this clinical relevant model, improvements of human cardiac transplantation and post-transplant contractile dysfunction, especially, could be investigated. [source] Lifespan extension by dietary restriction is not linked to protection against somatic DNA damage in Drosophila melanogasterAGING CELL, Issue 3 2009Ursula Edman Summary Dietary restriction (DR) has been shown to robustly extend lifespan in multiple species tested so far. The pro-longevity effect of DR is often ascribed to an increase in cellular defense against somatic damage, most notably damage by reactive oxygen species (ROS), considered a major cause of aging. Especially irreversible damage to DNA, the carrier of genetic information, is considered a critical causal factor in aging. Using a recently developed transgenic Drosophila melanogaster model system harboring a lacZ-plasmid construct that can be recovered in E. coli, spontaneous DNA mutation frequency in flies under DR and ad libitum conditions are measured. Three different DR conditions, imposed by manipulating levels of different types of yeast sources, were tested in females and males of two lacZ reporter gene lines. Feeding with the ROS producer paraquat at 1 mM resulted in a rapid accumulation of somatic mutations, indicating that the frequency of mutations at the lacZ locus is a reliable marker for increased oxidative stress. However, none of the DR conditions altered the accumulation of spontaneous mutations with age. These results suggest that the beneficial effects of DR are unlikely to be linked to protection against oxidative somatic DNA damage. [source] Alteration of amino acid metabolism in neuronal aggregate cultures exposed to hypoglycaemic conditionsJOURNAL OF NEUROCHEMISTRY, Issue 6 2002Paul Honegger Abstract The neuronal effects of glucose deficiency on amino acid metabolism was studied on three-dimensional cultures of rat telencephalon neurones. Transient (6 h) exposure of differentiated cultures to low glucose (0.25 mm instead of 25 mm) caused irreversible damage, as judged by the marked decrease in the activities of two neurone-specific enzymes and lactate dehydrogenase, 1 week after the hypoglycemic insult. Quantification of amino acids and ammonia in the culture media supernatants indicated increased amino acid utilization and ammonia production during glucose-deficiency. Measurement of intracellular amino acids showed decreased levels of alanine, glutamine, glutamate and GABA, while aspartate was increased. Added lactate (11 mm) during glucose deficiency largely prevented the changes in amino acid metabolism and ammonia production, and attenuated irreversible damage. Higher media levels of glutamine (4 mm instead of 0.25 mm) during glucose deprivation prevented the decrease of intracellular glutamate and GABA, while it further increased intracellular aspartate, ammonia production and neuronal damage. Both lactate and glutamine were readily oxidized in these neuronal cultures. The present results suggest that in neurones, glucose deficiency enhances amino acid deamination at the expense of transamination reactions. This results in increased ammonia production and neuronal damage. [source] Current Experimental Perspectives on the Clinical Progression of Alcoholic Liver DiseaseALCOHOLISM, Issue 10 2009Katja Breitkopf Chronic alcohol abuse is an important cause of morbidity and mortality throughout the world. Liver damage due to chronic alcohol intoxication initially leads to accumulation of lipids within the liver and with ongoing exposure this condition of steatosis may first progress to an inflammatory stage which leads the way for fibrogenesis and finally cirrhosis of the liver. While the earlier stages of the disease are considered reversible, cirrhotic destruction of the liver architecture beyond certain limits causes irreversible damage of the organ and often represents the basis for cancer development. This review will summarize current knowledge about the molecular mechanisms underlying the different stages of alcoholic liver disease (ALD). Recent observations have led to the identification of new molecular mechanisms and mediators of ALD. For example, plasminogen activator inhibitor 1 was shown to play a central role for steatosis, the anti-inflammatory adipokine, adiponectin profoundly regulates liver macrophage function and excessive hepatic deposition of iron is caused by chronic ethanol intoxication and increases the risk of hepatocellular carcinoma development. [source] OSCILLATING VANE GEOMETRY FOR SOFT SOLID GELS AND FOAMSJOURNAL OF TEXTURE STUDIES, Issue 6 2002C. SERVAIS ABSTRACT Several relationships between the torque and the stress exist for the vane geometry, but only a few equations have been proposed for the relationship between angular displacement and strain. In this study, an expression based on the infinite gap approximation for concentric cylinders is used and well-defined reference data are compared to oscillating vane data to validate the assumptions used. Gelatin gels are used for their property to stick to the wall and carrageenan gels are used to show that wall slip does not occur with oscillating vanes in serrated cup geometries. Shaving foams are used as a model low density, time and shear stable foam, which resists irreversible damage when loaded between serrated parallel plates. Results show that the assumptions used for the determination of stress and strain with the vane provide material viscoelastic properties that are not significantly different from reference values as obtained with concentric cylinders and parallel plates. [source] Stimulation of chlororespiration by heat and high light intensity in oat plantsPLANT CELL & ENVIRONMENT, Issue 8 2006MARÍA JOSÉ QUILES ABSTRACT High irradiance and moderate heat inhibit the activity of the photosynthetic apparatus of oat (Avena sativa L.) leaves. The incubation of oat leaves under high light intensity in conjunction with high temperatures strongly decreased the maximal quantum yield of photosystem (PS) II, indicating the close synergistic effect of both stress factors on PS II inhibition and the subsequent irreversible damage to the photosynthetic apparatus. The PS I A/B protein levels remained similar to control values in leaves incubated under high light intensity or moderate heat, and decreased only when both stress factors were simultaneously applied. Immunoblot analysis of thylakoid membranes using specific antibodies raised against the NDH-K subunit of the thylakoidal NADH dehydrogenase complex (NADH DH) and against plastid terminal oxidase (PTOX) revealed an increase in the amount of both proteins in response to high light intensity and/or heat treatments. In addition, these stress treatments were seen to stimulate the activity of electron donation by NADPH and ferredoxin to plastoquinone, the PTOX activity in plastoquinone oxidation and the NADH DH activity in thylakoid membranes. Incubation with n -propyl gallate (an inhibitor of PTOX) inhibited the increase of NDH-K and PTOX levels under high light intensity and heat, and slightly stimulated the activity of electron donation by NADPH and ferredoxin to plastoquinone. Antimycin A (an inhibitor of cyclic electron flow) increased the NADH DH activity and preserved the levels of NDH-K and PTOX in thylakoid membranes from leaves incubated under high light intensity and heat. The up-regulation of the PTOX and the thylakoidal NADH DH complex under these stress conditions supports a role for chlororespiration in the protection against high irradiance and moderate heat. [source] The assessment of fatigue damage on short-fiber-glass reinforced polyamides (PA) through the surface roughness evolutionPOLYMER COMPOSITES, Issue 4 2006J.A. Casado This paper analyses quantitatively the surface damage generated by the fatigue micromechanisms of the polyamide 6.6 (PA 6.6) reinforced with short fibre glass, with a series of specific tests for determining the surface roughness (RA) of the normalised specimens previously fatigue tested. The study has demonstrated that when the viscoelastic material is deformed in the fatigue process at a constant speed (d2,/dN2 = 0), crazing phenomena start to appear, distributed uniformly throughout its core. The effects of this damage, which is permanent and can be detected using sweep electron microscopy techniques (SEM), have been quantified through the measurement of the surface roughness of the specimens. In this way, the evolution of the roughness of the material is established as a qualitative index of the development of the nucleation of crazes and, thus, of irreversible damage, as these emerge towards the surface of the material. POLYM. COMPOS., 27:349,359, 2006. © 2006 Society of Plastics Engineers [source] Interferon-regulated chemokines as biomarkers of systemic lupus erythematosus disease activity: A validation studyARTHRITIS & RHEUMATISM, Issue 10 2009Jason W. Bauer Objective Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by unpredictable flares of disease activity and irreversible damage to multiple organ systems. An earlier study showed that SLE patients carrying an interferon (IFN) gene expression signature in blood have elevated serum levels of IFN-regulated chemokines. These chemokines were associated with more-severe and active disease and showed promise as SLE disease activity biomarkers. This study was designed to validate IFN-regulated chemokines as biomarkers of SLE disease activity in 267 SLE patients followed up longitudinally. Methods To validate the potential utility of serum chemokine levels as biomarkers of disease activity, we measured serum levels of CXCL10 (IFN,-inducible 10-kd protein), CCL2 (monocyte chemotactic protein 1), and CCL19 (macrophage inflammatory protein 3,) in an independent cohort of 267 SLE patients followed up longitudinally over 1 year (1,166 total clinic visits). Results Serum chemokine levels correlated with lupus activity at the current visit (P = 2 × 10,10), rising at the time of SLE flare (P = 2 × 10,3) and decreasing as disease remitted (P = 1 × 10,3); they also performed better than the currently available laboratory tests. Chemokine levels measured at a single baseline visit in patients with a Systemic Lupus Erythematosus Disease Activity Index of ,4 were predictive of lupus flare over the ensuing year (P = 1 × 10,4). Conclusion Monitoring serum chemokine levels in SLE may improve the assessment of current disease activity, the prediction of future disease flares, and the overall clinical decision-making. [source] | |||||||||||||