of attention-deficit/hyperactivity disorder

Purpose: Methylphenidate (MPH) derivative drugs are used because of psychostimulants effects on attention-deficit hyperactivity disorder in children and adults. As far as we know, toxic or anti-proliferative effects of MPH against cartilage tissue were not studied in the literature. The present study was carried out to investigate the possible effects of MPH on the proliferation, viability and differentiation of primary human chondrocytes, in vitro.Methods: Monolayer primary chondrocyte cultures were prepared using osteochondral tissue obtained from patients who underwent a total knee prosthesis operation. Stock solution of MPH was prepared and aliquots having 1-1000 mu M concentrations of the drug was composed. These solutions were applied to the wells containing cultured chondrocyte samples within the well plates. Control groups were composed of pure chondrocyte culture and no solution was added into them. All groups were evaluated at 24, 48 and 72 h in order to determine the possible negative effects of the drug on the chondrocytes. The data were evaluated by Tukey's honestly significantly different test following analysis of variance.Results: In the group where MPH was applied, it was found that viability, proliferation and stage-specific embryonic antigen-1 protein expression were decreased in comparison to the control group.Conclusions: It was emphasized that clinicians should not disregard the fact that this drug might suppress chondrocyte cell proliferation and chondrogenic differentiation

Chondrocyte proliferation, viability and differentiation is declined following administration of methylphenidate utilized for the treatment of attention-deficit/hyperactivity disorder.

PURPOSE: Methylphenidate (MPH) derivative drugs are used because of psychostimulants effects on attention-deficit hyperactivity disorder in children and adults. As far as we know, toxic or anti-proliferative effects of MPH against cartilage tissue were not studied in the literature. The present study was carried out to investigate the possible effects of MPH on the proliferation, viability and differentiation of primary human chondrocytes, in vitro. METHODS: Monolayer primary chondrocyte cultures were prepared using osteochondral tissue obtained from patients who underwent a total knee prosthesis operation. Stock solution of MPH was prepared and aliquots having 1-1000 µM concentrations of the drug was composed. These solutions were applied to the wells containing cultured chondrocyte samples within the well plates. Control groups were composed of pure chondrocyte culture and no solution was added into them. All groups were evaluated at 24, 48 and 72 h in order to determine the possible negative effects of the drug on the chondrocytes. The data were evaluated by Tukey's honestly significantly different test following analysis of variance. RESULTS: In the group where MPH was applied, it was found that viability, proliferation and stage-specific embryonic antigen-1 protein expression were decreased in comparison to the control group. CONCLUSIONS: It was emphasized that clinicians should not disregard the fact that this drug might suppress chondrocyte cell proliferation and chondrogenic differentiation

Lipid peroxidation and antoxidants in preeclampsia

Objective: To determine the changes in plasma levels of lipid peroxide, vitamin E and vitamin C in women with preeclampsia and to investigate their relationship with diastolic blood pressure. Study Design: Cross sectional study consisting of 22 preeclamptic and 21 healthy pregnant women. Fasting venous blood samples were collected during the antepartum period and plasma levels of malondialdehyde, alpha-tocopherol and ascorbic acid were measured. Results: In the preeclamptic group malondialdehyde, a lipid peroxidation product, was significantly increased, while vitamins E and C were significantly decreased compared to healthy pregnant women. A strong correlation was detected between malondialdehyde and antioxidant factors (vitamins E and C) with blood pressure. Conclusion: Our findings are consistent with previous studies suggesting that lipid peroxidation is an important factor in the pathogenesis of preeclampsia. In preeclampsia, antioxidant nutrients are excessively utilised to counteract the cellular changes mediated by free radicals. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved

Apoptosis in the erectile tissues of diabetic and healthy rats

Objective To compare the frequency of apoptosis in the erectile tissue of chronic diabetic and healthy rats

The effect of sildenafil, a phosphodiesterase-5 inhibitor, on acetic acid-induced colonic inflammation in the rat

Sildenafil, a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE)5, has a relaxant effect on the smooth muscle cells of the arterioles supplying the human corpus cavernosum acting via nitric oxide (NO)-dependent mechanism. This study aimed to investigate the possible protective effect of sildenafil citrate on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of acetic acid-induced colitis

Phosphodiesterase-5 inhibition by sildenafil citrate in a rat model of bleomycin-induced lung fibrosis

Sildenafil, a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE)5, has a relaxant effect on the smooth muscle cells of the arterioles supplying the human corpus cavernosum acting via nitric oxide (NO)-dependent mechanism. This study aimed to investigate the possible protective effect of sildenafil citrate on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of bleomycin-induced lung fibrosis. Lung fibrosis was induced by intratracheal administration of 0.1 ml of bleomycin hydrochloride (5 mg/kg in 0.9% NaCl) under anesthesia to Sprague-Dawley rats (200-250 g; n =7-8 per group). Control rats received an equal volume of saline intratracheally. In the treatment groups, the rats were treated with either sildenafil citrate (10 mg/kg per day; subcutaneously) or saline for 14 days. Another group of rats were administered subcutaneously with N(G)-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg in 0.9% NaCI) 5 min after sildenafil injections. After decapitation, the lungs were excised and taken for microscopic evaluation or stored for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity, and for the assessment of apoptosis. Trunk blood was collected for the assessment of serum tumor necrosis factor (TNF)-alpha and interleukin (1)-1 beta levels. In the group with lung fibrosis, the lung tissue was characterized by microscopic lesions, increased lipid peroxidation with a concomitant reduction in GSH content, increased MPO activity and apoptosis. Serum TNF-alpha and IL-1 beta levels were higher in the lung fibrosis group compared to control values. Sildenafil reversed tissue MDA levels, MPO activity and serum pro-inflammatory cytokine levels, and preserved GSH content although its effect on the extent of tissue lesion and apoptosis was not statistically significant. Treatment with L-NAME reversed the effect of sildenafil on GSH content. In conclusion, sildenafil citrate administration to rats with bleomycin-induced lung fibrosis seems to be beneficial via prevention of lipid peroxidation, cytokine production and/or release and neutrophil accumulation. (C) 2009 Elsevier Ltd. All rights reserved

The role of nitric oxide in pediatric patients with portal hypertension

The hyperdynamic circulation of cirrhosis and portal hypertension has been postulated to be due to the vasodilatory effects of nitric oxide. However, there have been conflicting results in adults and no studies in children. We aimed to measure the nitric oxide level in serum of pediatric patients with portal hypertension with and without cirrhosis, in order to assess its role in the development of hemodynamic changes. We measured nitric oxide levels in 41 pediatric patients (21 patients with intrahepatic portal hypertension and 20 with extrahepatic portal hypertension). The mean age of the study population was 11.2 +/- 4.6 years; 53 per cent were female. Twenty healthy children were included as a control group. Nitric oxide levels were measured by Boehringer-Mannheim colorimetric assay and the statistical significance was calculated by Kruskal-Wallis one-way ANOVA. Significantly higher nitric oxide levels were found in patients independent of the type of portal hypertension compared with the control group (29.4 +/- 6 in patients with intrahepatic portal hypertension, 29.5 +/- 5.8 in patients with extrahepatic portal hypertension, and 23.6 +/- 6.5 in the control group; p < 0.007). These data showed a difference between the groups and suggest that nitric oxide, predominantly independent of cirrhosis, plays a primary role in the pathogenesis of portal hypertension