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Important Clinical Problem (important + clinical_problem)
Selected AbstractsDetection of contact hypersensitivity to corticosteroids in allergic contact dermatitis patients who do not respond to topical corticosteroidsCONTACT DERMATITIS, Issue 2 2005Müzeyyen Gönül The delayed hypersensitivity development against topical corticosteroids which are used in allergic contact dermatitis (ACD) treatment is an important clinical problem. In our study, 41 ACD patients who did not show any response to topical corticosteroid treatment were patch tested with corticosteroid series and the commercial preparations of corticosteroids and their vehicles. In corticosteroid series, there were budesonide, bethametasone-17-valerate, triamcinolone acetonide, tixocortol pivalate, alclomethasone-17-21-dipropionate, clobetasole-17-propionate, dexamethasone-21-phosphate disodium and hydrocortisone-17-butyrate. We detected positive reaction to corticosteroids in 9 of our cases (22%) (5 single and 4 multiple). The sensitivity was mostly produced by tixocortol pivalate (6 patients). This was followed by triamcinolone acetonide (2 patients) budesonide (2 patients), alclomethasone dipropionate (2 patients), dexamethasone 21 phosphate disodium (2 patients) and betamethasone-17-valerate (1 patient). As a result, it should not be forgotten that the corticosteroids used to treat ACD patients may cause ACD themselves. In ACD patients who did not respond to corticosteroid treatment, routinely applying patch test with corticosteroids should be helpful in directing the treatment. [source] Calcium in the mechanism of ammonia-induced astrocyte swellingJOURNAL OF NEUROCHEMISTRY, Issue 2009Arumugam R. Jayakumar Abstract Brain edema, due largely to astrocyte swelling, is an important clinical problem in patients with acute liver failure. While mechanisms underlying astrocyte swelling in this condition are not fully understood, ammonia and associated oxidative/nitrosative stress appear to be involved. Mechanisms responsible for the increase in reactive oxygen/nitrogen species (RONS) and their role in ammonia-induced astrocyte swelling, however, are poorly understood. Recent studies have demonstrated a transient increase in intracellular Ca2+ in cultured astrocytes exposed to ammonia. As Ca2+ is a known inducer of RONS, we investigated potential mechanisms by which Ca2+ may be responsible for the production of RONS and cell swelling in cultured astrocytes after treatment with ammonia. Exposure of cultured astrocytes to ammonia (5 mM) increased the formation of free radicals, including nitric oxide, and such increase was significantly diminished by treatment with the Ca2+ chelator 1,2-bis-(o -aminophenoxy)-ethane- N,N,- N,,N, -tetraacetic acid tetraacetoxy-methyl ester (BAPTA). We then examined the activity of Ca2+ -dependent enzymes that are known to generate RONS and found that ammonia significantly increased the activities of NADPH oxidase (NOX), constitutive nitric oxide synthase (cNOS), and phospholipase A2 (PLA2) and such increases in activity were significantly diminished by BAPTA. Pre-treatment of cultures with 7-nitroindazole, apocyanin, and quinacrine, respective inhibitors of cNOS, NOX, and PLA2, all significantly diminished RONS production. Additionally, treatment of cultures with BAPTA or with inhibitors of cNOS, NOX, and PLA2 reduced ammonia-induced astrocyte swelling. These studies suggest that the ammonia-induced rise in intracellular Ca2+ activates free radical producing enzymes that ultimately contribute to the mechanism of astrocyte swelling. [source] The effect of skeletal maturity on the regenerative function of intrinsic ACL cellsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2010Ashley N. Mastrangelo Abstract Anterior cruciate ligament (ACL) injuries are an important clinical problem, particularly for adolescent patients. The effect of skeletal maturity on the potential for ACL healing is as yet unknown. In this study, we hypothesized that fibroblastic cells from the ACLs of skeletally immature animals would proliferate and migrate more quickly than cells from adolescent and adult animals. ACL tissue from skeletally immature, adolescent, and adult pigs and sheep were obtained and cells obtained using explant culture. Cell proliferation within a collagen,platelet scaffold was measured at days 2, 7, and 14 of culture using AM MTT assay. Cellular migration was measured at 4 and 24 h using a modified Boyden chamber assay, and cell outgrowth from the explants also measured at 1 week. ACL cells from skeletally immature animals had higher proliferation between 7 and 14 days (p,<,0.01 for all comparisons) and higher migration potential at all time points in both species (p,<,0.01 for all comparisons). ACL cells from skeletally immature animals have greater cellular proliferation and migration potential than cells from adolescent or adult animals. These experiments suggest that skeletal maturity may influence the biologic repair capacity of intrinsic ACL cells. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:644,651, 2010 [source] Median liver lobe of woodchuck as a model to study hepatic outflow obstruction: a pilot studyLIVER INTERNATIONAL, Issue 9 2008Uta Dahmen Abstract Background: Hepatic vein outflow obstruction represents an important clinical problem in living-liver transplantation. An animal model is required to study the influence of outflow obstruction on the intrahepatic regulation of liver perfusion and the subsequent effects on liver injury and recovery during liver regeneration. The size of woodchucks enables the use of standard clinical imaging procedures. Aim: This study aims at describing hepatic vascular and territorial anatomy of the woodchuck liver based on a virtual three-dimensional (3D) visualization of the hepatic vascular tree. Methods: Woodchucks (n=6) were subjected to an all-in-one computed tomography (CT) after contrasting the vascular and the biliary tree. CT-images were used for 3D-reconstruction of hepatic and portal veins and calculation of the corresponding portal and hepatic vein territories and their respective volume using hepavision (MeVisLab). A virtual resection was performed following the Cantlie-line and territories at risk were calculated. Results: The median lobe of the woodchuck liver has a similar vascular supply and drainage as the human liver with two portal (right and left median portal vein) and three hepatic veins (left, middle and right median hepatic vein). The corresponding portal and hepatic vein subterritories are of a similar relative size compared with the human liver. Virtual splitting of the median lobe of the woodchuck liver revealed areas at risk of focal outflow obstruction, as observed clinically. Conclusion: The median liver lobe of the woodchuck represents, to a small extent, the hepatic vascular anatomy of the human liver and is therefore a suitable potential model to correlate repeated imaging of impaired liver perfusion with histomorphological findings of liver damage and regeneration. [source] SLE, atherosclerosis and cardiovascular diseaseJOURNAL OF INTERNAL MEDICINE, Issue 6 2005J. FROSTEGÅRD Abstract. Atherosclerosis is an inflammatory disease and the major cause of cardiovascular disease (CVD) in general. Atherosclerotic plaques are characterized by the presence of activated immune competent cells, but antigens and underlying mechanisms causing this immune activation are not well defined. During recent years and with improved treatment of acute disease manifestations, it has become clear that the risk of CVD is very high in a prototypic autoimmune disease, systemic lupus erythematosus (SLE). SLE-related CVD and atherosclerosis are important clinical problems but may in addition also shed light on how immune reactions are related to premature atherosclerosis and atherothrombosis. A combination of traditional and nontraditional risk factors, including dyslipidaemia (and to a varying degree hypertension, diabetes and smoking), inflammation, antiphospholipid antibodies (aPL) and lipid oxidation are related to CVD in SLE. Premature atherosclerosis in some form leading to atherothrombosis is likely to be a major underlying mechanism, though distinctive features if any, of SLE-related atherosclerosis when compared with ,normal' atherosclerosis are not clear. One interesting possibility is that factors such as inflammation or aPL make atherosclerotic lesions in autoimmune disease more prone to rupture than in ,normal' atherosclerosis. Whether premature atherosclerosis is a general feature of SLE or only affects a subgroup of patients remains to be demonstrated. Treatment of SLE patients should also include a close monitoring of traditional risk factors for CVD. In addition, attention should also be paid to nontraditional risk factors such as inflammation and SLE-related factors such as aPL. Hopefully novel therapeutic principles will be developed that target the causes of the inflammation and immune reactions present in atherosclerotic lesions. [source] Respiratory complications related to bulbar dysfunction in motor neuron diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 4 2001S. Hadjikoutis Bulbar dysfunction resulting from corticobulbar pathway or brainstem neuron degeneration is one of the most important clinical problems encountered in motor neuron disease (MND) and contributes to various respiratory complications which are major causes of morbidity and mortality. Chronic malnutrition as a consequence of bulbar muscle weakness may have a considerable bearing on respiratory muscle function and survival. Abnormalities of the control and strength of the laryngeal and pharyngeal muscles may cause upper airway obstruction increasing resistance to airflow. Bulbar muscle weakness prevents adequate peak cough flows to clear airway debris. Dysphagia can lead to aspiration of microorganisms, food and liquids and hence pneumonia. MND patients with bulbar involvement commonly display an abnormal respiratory pattern during swallow characterized by inspiration after swallow, prolonged swallow apnoea and multiple swallows per bolus. Volitional respiratory function tests such as forced vital capacity can be inaccurate in patients with bulbofacial weakness and/or impaired volitional respiratory control. Bulbar muscle weakness with abundant secretions may increase the risk of aspiration and make successful non-invasive assisted ventilation more difficult. We conclude that an evaluation of bulbar dysfunction is an essential element in the assessment of respiratory dysfunction in MND. [source] | |||||||||||||