Psoriasis de l'enfant. [Pediatric psoriasis]

Psoriasis is a cutaneous inflammatory disorder that may be seen in childhood, sometimes complicated by serious forms. The diagnosis is often more difficult than in adults, because initial lesions may be atypical or pauci-symptomatic. Psoriasis is a chronic disease, with a prognosis worse than atopic dermatitis; patients and their family generally need long term therapy and supportive care. The treatment is not different from that of the adult, but is less studied and less validated by specific pediatric controlled studies

Anaphylaxis to the carbohydrate carboxymethylcellulose in parenteral corticosteroid preparations

BACKGROUND: Carboxymethylcellulose is a carbohydrate widely used as additive in tablets, cosmetics, some injectable hormone formulations, food (as E466) and as active principle in hydrocolloid dressings. Anaphylaxis to carboxymethylcellulose in parenteral corticosteroid preparations has previously been reported. Typically, skin tests were positive in such cases, occasionally specific IgE or histamine release have been demonstrated. CASE REPORT: We report on 3 patients who suffered from anaphylactic symptoms after local injection of corticosteroid preparations. Intracutaneous skin tests with carboxymethylcellulose were positive; in 2, sulfidoleukotriene release could be measured in the cellular antigen stimulation test (CAST). Specific IgE could not be identified. Oral provocation tests with typical doses of carboxymethylcellulose as found in food and tablets were negative. CONCLUSION: In patients with anaphylaxis to parenteral administration of carboxymethylcellulose, small amounts are tolerated by the oral route. Skin tests and CAST are useful diagnostic tools

Free radicals, metals and antioxidants in oxidative stress-induced cancer

Oxygen-free radicals, more generally known as reactive oxygen species (ROS) along with reactive nitrogen species (RNS) are well recognised for playing a dual role as both deleterious and beneficial species. The "two-faced" character of ROS is substantiated by growing body of evidence that ROS within cells act as secondary messengers in intracellular signalling cascades, which induce and maintain the oncogenic phenotype of cancer cells, however, ROS can also induce cellular senescence and apoptosis and can therefore function as anti-tumourigenic species. The cumulative production of ROS/RNS through either endogenous or exogenous insults is termed oxidative stress and is common for many types of cancer cell that are linked with altered redox regulation of cellular signalling pathways. Oxidative stress induces a cellular redox imbalance which has been found to be present in various cancer cells compared with normal cells; the redox imbalance thus may be related to oncogenic stimulation. DNA mutation is a critical step in carcinogenesis and elevated levels of oxidative DNA lesions (8-OH-G) have been noted in various tumours, strongly implicating such damage in the etiology of cancer. It appears that the DNA damage is predominantly linked with the initiation process. This review examines the evidence for involvement of the oxidative stress in the carcinogenesis process. Attention is focused on structural, chemical and biochemical aspects of free radicals, the endogenous and exogenous sources of their generation, the metal (iron, copper, chromium, cobalt, vanadium, cadmium, arsenic, nickel)-mediated formation of free radicals (e.g. Fenton chemistry), the DNA damage (both mitochondrial and nuclear), the damage to lipids and proteins by free radicals, the phenomenon of oxidative stress, cancer and the redox environment of a cell, the mechanisms of carcinogenesis and the role of signalling cascades by ROS; in particular. ROS activation of AP-1 (activator protein) and NF-kappa B (nuclear factor kappa B) signal transduction pathways, which, in turn lead to the transcription of genes involved in cell growth regulatory pathways. The role of enzymatic (superoxide dismutase (Cu. Zn-SOD. Mn-SOD), catalase, glutathione peroxidase) and non-enzymatic antioxidants (Vitamin C, Vitamin E, carotenoids, thiol antioxidants (glutathione, thioredoxin and lipoic acid), flavonoids, selenium and others) in the process of careinogenesis as well as the antioxidant interactions with various regulatory factors, including Ref-1, NF-kappa B, AP-1 are also reviewed. 2006 Elsevier Ireland Ltd. All rights reserved

Role of oxygen radicals in DNA damage and cancer incidence

The development of cancer in humans and animals is a multistep process. The complex series of cellular and molecular changes participating in cancer development are mediated by a diversity of endogenous and exogenous stimuli. One type of endogenous damage is that arising from intermediates of oxygen (dioxygen) reduction - oxygen-free radicals (OFR), which attacks not only the bases but also the deoxyribosyl backbone of DNA. Thanks to improvements in analytical techniques, a major achievement in the understanding of carcinogenesis in the past two decades has been the identification and quantification of various adducts of OFR with DNA. OFR are also known to attack other cellular components such as lipids, leaving behind reactive species that in turn can couple to DNA bases. Endogenous DNA lesions are genotoxic and induce mutations. The most extensively studied lesion is the formation of 8-OH-dG. This lesion is important because it is relatively easily formed and is mutagenic and therefore is a potential biomarker of carcinogenesis. Mutations that may arise from formation of 8-OH-dG involve GC. TA transversions. In view of these findings, OFR are considered as an important class of carcinogens. The effect of OFR is balanced by the antioxidant action of non-enzymatic antioxidants as well as antioxidant enzymes. Non-enzymatic antioxidants involve vitamin C, vitamin E, carotenoids (CAR), selenium and others. However, under certain conditions, some antioxidants can also exhibit a pro-oxidant mechanism of action. For example, beta-carotene at high concentration and with increased partial pressure of dioxygen is known to behave as a pro-oxidant. Some concerns have also been raised over the potentially deleterious transition metal ion-mediated (iron, copper) pro-oxidant effect of vitamin C. Clinical studies mapping the effect of preventive antioxidants have shown surprisingly little or no effect on cancer incidence. The epidemiological trials together with in vitro experiments suggest that the optimal approach is to reduce endogenous and exogenous sources of oxidative stress, rather than increase intake of anti-oxidants. In this review, we highlight some major achievements in the study of DNA damage caused by OFR and the role in carcinogenesis played by oxidatively damaged DNA. The protective effect of antioxidants against free radicals is also discussed

Pseudoxanthoma elasticum-like papillary dermal elastolysis: a large case series with clinicopathological correlation

Background: Pseudoxanthoma elasticum (PXE)-like papillary dermal elastolysis (PDE) is a rare acquired elastic tissue disorder. To date, less than 20 cases have been reported. Objective: We report a case series of 17 patients presenting with PXE-like PDE and discuss the clinicopathological correlation. Methods: Seventeen cases of PXE-like PDE were collected prospectively and evaluated for common demographic, clinical, and histopathological features. Results: All patients were women with a mean age of 61.8 years. The lateral sides and back of neck were the most common sites of involvement (100%), followed by the supraclavicular region (41.2%) and the axilla (35.3%). Systemic involvement was absent in all cases, and in 7 patients the discovery of PXE-like PDE was an incidental finding. The main histopathologic features included complete loss (82.4%) or marked reduction (17.6%) of elastic fibers in the papillary dermis and the presence of melanophages in the same zone (88.2%). Limitations: Our results require validation with a larger series. Conclusions: Our findings help to differentiate PXE-like PDE from similar elastic tissue disorders based on the selective elastic tissue elimination in the papillary dermis and the presence of melanophages in the same zone as a possible consequence of subclinical junctional photodamage. PXE-like PDE is likely underdiagnosed rather than rare, and dermatologists should be aware of its similarity to inherited PXE to spare unnecessary investigations because of the lack of systemic involvement. Clinicopathologic correlation is critical as hematoxylin-eosin staining is nonspecific and elastic tissue stains are necessary to make the correct diagnosi

The physiological period length of the human circadian clock in vivo is directly proportional to period in human fibroblasts.

Diurnal behavior in humans is governed by the period length of a circadian clock in the suprachiasmatic nuclei of the brain hypothalamus. Nevertheless, the cell-intrinsic mechanism of this clock is present in most cells of the body. We have shown previously that for individuals of extreme chronotype ("larks" and "owls"), clock properties measured in human fibroblasts correlated with extreme diurnal behavior