Pros and cons of using systemic acitretin in the paediatric population.

Acitretin, a synthetic analogue of vitamin A is widely used in dermatology. It has an important role in the treatment of psoriasis and keratinization disorders. In adults its safety and efficacy has been proven in many studies, but there are some concerns regarding the use of acitretin in paediatric population, especially in high doses and as a long-term therapy. In this article we present the main indications of acitretin in children as well as the positive and negative aspects of acitretin treatment in this age population.

Blue Light in Dermatology.

Phototherapy is an important method of dermatological treatments. Ultraviolet (280-400 nm) therapy is of great importance; however, there are concerns of its long-term use, as it can lead to skin aging and carcinogenesis. This review aims to evaluate the role and the mechanism of action of blue light (400-500 nm), a UV-free method. The main mediators of cellular responses to blue light are nitric oxide (NO) and reactive oxygen species (ROS). However, the detailed mechanism is still not fully understood. It was demonstrated that blue light induces an anti-inflammatory and antiproliferative effect; thus, it may be beneficial for hyperproliferative and chronic inflammatory skin diseases such as atopic dermatitis, eczema, and psoriasis. It was also found that blue light might cause the reduction of itching. It may be beneficial on hair growth and may be used in the treatment of acne vulgaris by reducing follicular colonization of Propionibacterium acnes. Further studies are needed to develop accurate protocols, as the clinical effects depend on the light parameters as well as the treatment length. There are no major adverse effects observed yet, but long-term safety should be monitored as there are no studies considering the long-term effects of blue light on the skin.

Interactions of free copper (II) ions alone or in complex with iron (III) ions with erythrocytes of marine fish Dicentrarchus labrax.

As a consequence of human activity, various toxicants - especially metal ions - enter aquatic ecosystems and many fish are exposed to considerable levels. As the free ion and in some complexes, there is no doubt that copper promotes damage to cellular molecules and structures through radical formation. Therefore, we have investigated the influence of copper uptake by the red blood of the sea bass (Dicentrarchus labrax), and its oxidative action and effects on cells in the presence of complexed and uncomplexed Fe3+ ions. Erythrocytes were exposed to various concentrations of CuSO4, Fe(NO3)3, and K3Fe(CN)6 for up to 5h, and the effects of copper ions alone and in the combination with iron determined. The results show that inside the cells cupric ion interacts with hemoglobin, causing methemoglobin formation by direct electron transfer from heme Fe2+ to Cu2+. Potassium ferricyanide as a source of complexed iron decreases Met-Hb formation induced by copper ions unlike Fe(NO3)3. We also found that incubation of fish erythrocytes with copper increased hemolysis of cells. But complexed and uncomplexed iron protected the effect of copper. CuSO4 increased the level of lipid peroxidation and a protective effect on complexed iron was observed. Incubation of erythrocytes with copper ions resulted in the loss of a considerable part of thiol content at 10 and 20 microM. This effect was decreased by potassium ferricyanide and Fe(NO3)3 only after 1 and 3h of incubation. The level of nuclear DNA damage assayed by comet assay showed that 20 microM CuSO4 as well as 20 microM Fe(NO3)3 and 10 mM K3Fe(CN)6 induce single- and double-strand breaks. The lower changes were observed after the exposure of cells to K3Fe(CN)6. The data suggest that complexed iron can act protectively against copper ions in contrast to Fe(NO3)3.

Validation of a sham manipulative procedure for the cervical spine for use in clinical trials.

OBJECTIVE: To develop a sham manipulation procedure for the cervical spine for use in randomized clinical trials of cervical disorders. METHODS: A single-group, single-intervention study design was used. Adult neck pain subjects underwent a screening examination that included palpation for a site of cervical spine joint dysfunction. Eligible subjects underwent measurements of regional cervical ranges of motion as well as pressure algometry (tenderness) at the site of cervical joint dysfunction. Subjects were instructed that they would receive one of several types of manipulative procedures. A newly developed sham manipulation was delivered once. Subjects were then remeasured for ranges of motion and tenderness. They were asked if they had experienced any pain during the procedure, if they had experienced a "cavitation" sound, and if they thought that the procedure they received was a "real" manipulation. Finally, they were debriefed as to the deception involved in this study. A prior level of 65% was set for endorsement that the procedure was a real manipulation. Changes in pre-post measures of ranges of motion and tenderness were analyzed descriptively for clinically important differences. RESULTS: Twenty eligible subjects were included (12 males, 8 females) with an average age of 30.4 (2.8) years. Twelve of the subjects were not students, with 3 of these having no prior experience with chiropractic treatment; 8 were students. Of the total sample (N = 19), 8 (42.1%) indicated that the procedure was a "real adjustment"; of the 12 nonstudents, 8 (58.3%) indicated similarly. None of the procedures in the final sample resulted in a cavitation, and none of the subjects registered the procedure as painful. None of the measures for ranges of motion or tenderness showed clinically important changes. CONCLUSIONS: The sham cervical manipulation studied here appears to approximate the necessary features of a placebo maneuver in that it is perceived by a majority of nonstudent neck pain subjects to be a real manipulation, although it does not produce any important change in cervical status. The small sample size of nonstudent participants precludes a strong recommendation for this procedure at this time.

Prolonged treatment with glucocorticoid dexamethasone suppresses melatonin production by the chick pineal gland and retina.

The chick pineal gland and retina synthesize melatonin in a circadian rhythm with high levels during the night. The rhythmic changes in the hormone production result predominantly from the fluctuation in the activity of serotonin N-acetyltransferase (AA-NAT), a penultimate and key regulatory enzyme in melatonin biosynthesis. The aim of this study was to analyze the effects of an acute and prolonged in vivo treatment with a glucocorticoid dexamethasone (4 mg/kg, ip) on the nocturnal increase in AA-NAT activity in chick pineal gland and retina. In acute experiments, dexamethasone (single dose)-injected chicks were killed after 2 h, while in prolonged experiments the glucocorticoid was given once daily for 7 days and the animals were killed 26-32 h after the last injection. Acute administration of dexamethasone did not affect AA-NAT activity in the chick pineal gland and retina. In the pineal glands and retinas of chicks that were treated with dexamethasone for one week and then killed at the end of the light phase of the 12:12 h light-dark cycle, AA-NAT activity was significantly higher than the enzyme activity found in tissues isolated from the vehicle-treated (control) animals. In addition to that, the nocturnal increase in pineal and, to a lower extent, retinal AA-NAT activity was significantly lower in dexamethasone-treated birds when compared with the respective control groups. It is suggested that prolonged treatment of animals with dexamethasone reduces the amplitude of the rhythmic melatonin production, a phenomenon which may affect chronobiological processes being under control of this hormone.