The 15d­PGJ2 hydrogel ameliorates atopic dermatitis through suppression of the immune response.

The present study examined the efficacy of the topical 15d­PGJ2­poloxamer 407 hydrogel in an atopic dermatitis (AD) animal model. The 15d­PGJ2 hydrogel was prepared and characterized. The examined rats possessed AD­Like cutaneous lesions, which were induced using 2,4­dinitrochlorobenzene, the rats were then treated with a hydrogel vehicle, 15d­PGJ2 hydrogel or tacrolimus for 14 days. The rats were sacrificed and blood samples were collected to quantify the IgE levels. Subsequently, skin biopsies were stained with toluidine blue to identify mast cells and immunohistochemistry was performed for ROR­Î³t and TNF­α. Histological analyses demonstrated that 15d­PGJ2 hydrogel significantly decreased mast cell infiltration (P<0.05) when compared with the AD­group. Tacrolimus at 0.1% exhibited decreased mast cell infiltration; however, this difference was not statistically significant from the AD­group. Topical 15d­PGJ2 hydrogel and Tacrolimus 0.1% significantly reduced the serum levels of IgE (P<0.05) compared with the AD­group. Immunohistochemistry revealed a significant decrease in ROR­Î³t and TNF­α positive cell expression (P<0.05) in the 15d­PGJ2 hydrogel group compared with the AD­group. In summary, topical administration of 15d­PGJ2 hydrogel had a beneficial effect on AD symptoms, suggesting that this formulation may be a useful strategy for the treatment of AD.

Effect of glucagon-like peptide 2 on hepatic, renal, and intestinal disposition of 1-chloro-2,4-dinitrobenzene.

The ability of the liver, small intestine, and kidney to synthesize and subsequently eliminate dinitrophenyl-S-glutathione (DNP-SG), a substrate for multidrug resistance-associated protein 2 (Mrp2), was assessed in rats treated with glucagon-like peptide 2 (GLP-2, 12 µg/100 g b.wt. s.c. every 12 h for 5 consecutive days). An in vivo perfused jejunum model with simultaneous bile and urine collection was used. A single intravenous dose of 30 µmol/kg b.wt. 1-chloro-2,4-dinitrobenzene (CDNB) was administered, and its conjugate, DNP-SG, and dinitrophenyl cysteinyl glycine (DNP-CG), resulting from the action of γ-glutamyltransferase on DNP-SG, were determined in bile, intestinal perfusate, and urine by high-performance liquid chromatography. Tissue content of DNP-SG was also assessed in liver, intestine, and kidneys. Biliary excretion of DNP-SG+DNP-CG was decreased in GLP-2 rats with respect to controls. In contrast, their intestinal excretion was substantially increased, whereas urinary elimination was not affected. Western blot and real-time polymerase chain reaction studies revealed preserved levels of Mrp2 protein and mRNA in liver and renal cortex and a significant increase in intestine in response to GLP-2 treatment. Tissue content of DNP-SG detected 5 min after CDNB administration was decreased in liver, increased in intestine, and unchanged in kidney in GLP-2 versus control group, consistent with GLP-2-induced down-regulation of expression of glutathione transferase (GST) Mu in liver and up-regulation of GST-Alpha in intestine at both protein and mRNA levels. In conclusion, GLP-2 induced selective changes in hepatic and intestinal disposition of a common GST and Mrp2 substrate administered systemically that could be of pharmacological or toxicological relevance under therapeutic treatment conditions.

Reactive oxygen species in bovine oocyte maturation in vitro.

The role of reactive oxygen species (ROS) in the in vitro maturation (IVM) of oocytes remains controversial. The aim of the present study was to determine possible fluctuations in ROS production during bovine oocyte IVM in the presence of different modulators of ROS generation. Cumulus-oocyte complexes were cultured in medium 199 (control) in the absence or presence of 0.6 mM cysteine, 1 mM 1-choro-2,4-dinitro benzene (CDNB), 2 microM diphenyliodonium, 0.5 mM N-nitro-L-arginine methyl ester or 10 microM sodium nitroprusside (SNP) at 39 degrees C, in 5% CO2 in humidified air for 22 h. In addition, the respiratory chain effectors potassium cyanide (KCN; 1 mM) and carbonyl cyanide m-chlorophenylhydrazone (0.42 microM) were used. Meiotic maturation was determined by the presence of MII. ROS production was evaluated in denuded oocytes at different time points as the ratio of 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA) to fluorescein diacetate (FDA). ROS levels, expressed as DCHF-DA:FDA, fluctuated throughout the 22 h of maturation depending on the treatment applied. At 12 h incubation in the presence of KCN and SNP, ROS levels were increased, whereas ROS levels after 12 h in the presence of cysteine were reduced (P<0.05). Both CDNB and SNP impaired meiotic progression. The higher metabolic activity demand during bovine oocyte maturation coincides with a concomitant reduction in ROS generation. These results suggest that 12 h would be a critical point for bovine oocyte IVM because it is closely related to the production of ROS at this time.

Inhibition of cytosolic glutathione S-transferase activity from rat liver by copper.

H(2)O(2) inactivation of particular GST isoforms has been reported, with no information regarding the overall effect of other ROS on cytosolic GST activity. The present work describes the inactivation of total cytosolic GST activity from liver rats by the oxygen radical-generating system Cu(2+)/ascorbate. We have previously shown that this system may change some enzymatic activities of thiol proteins through two mechanisms: ROS-induced oxidation and non-specific Cu(2+) binding to protein thiol groups. In the present study, we show that nanomolar Cu(2+) in the absence of ascorbate did not modify total cytosolic GST activity; the same concentrations of Cu(2+) in the presence of ascorbate, however, inhibited this activity. Micromolar Cu(2+) in either the absence or presence of ascorbate inhibited cytosolic GST activity. Kinetic studies show that GSH but no 1-chloro-2,4-dinitrobenzene prevent the inhibition on cytosolic GST induced by micromolar Cu(2+) either in the absence or presence of ascorbate. On the other hand, NEM and mersalyl acid, both thiol-alkylating agents, inhibited GST activity with differential reactivity in a dose-dependent manner. Taken together, these results suggest that an inhibitory Cu(2+)-binding effect is likely to be negligible on the overall inhibition of cytosolic GST activity observed by the Cu(2+)/ascorbate system. We discuss how modification of GST-thiol groups is related to the inhibition of cytosolic GST activity.

Nonspecific cell-mediated immunity in patients with epidermodysplasia verruciformis.

Epidermodysplasia verruciformis (EV) is a rare disease that usually begins in childhood and is characterized by a generalized infection by human papilloma virus (HPV), frequent associations with cutaneous carcinomas, and abnormalities of cell-mediated immunity (CMI). We studied nonspecific CMI in 13 patients with EV by bacterial skin tests, allergic reactions to dinitrochlorobenzene (DNCB), measurement of responses to phytohemagglutinin (PHA), and quantification of T lymphocytes and T lymphocytes subsets in peripheral blood. Impairment of CMI was manifested by the cutaneous anergy to a variety of common skin antigens and, by the reduction of the lymphocyte transformation to PHA. There were no correlation between the severity of cases and abnormalities of CMI in our patients, however; the impairment of CMI was lower in cases of short duration, suggesting that the impairment of CMI in EV might reflect a long period of disease.

Inmunoterapia tópica en el tratamiento de la alopecia areata / Topical immunotherapy in alopecia areata treatment

La alopécia areata (AA) es una patología realtivamente frecuente del folículo piloso. Su etiología, si bien es desconocida, probablemente corresponda a un fenómeno autoinmune, aunque factores genéticos y ambientales también estarían involucrados. La inmunoterapia tópica es la modalidad terapéutica más efectiva y aceptada en el tratamiento de la AA crónica severa. La inmunoterapia tópica se define como la inducción y posterior provocación periódica de una dermatitis de contacto alérgica, a través de la aplicación de un potente alergeno de contacto en una zona cutánea determinada. Han sido utilizados tres alergenos de contacto en el tratamiento de la alopecia areata: dinitroclorobenceno (DNCB), dibutil éster del ácido escuárico (SADBE) y difenciprona (DPC). En el presente trabajo se describen las principales características de estos agentes tópicos