Analysis of factors that may affect the enzymatic profile of gingival crevicular fluid: sampling technique, sequential sampling and mode of data presentation

To evaluate the possible effect of sampling technique and sequential sampling on gingival crevicular fluid (GCF) volume and myeloperoxidase (MPO) activity, 14 patients presenting at least two symmetrical maxillary sites with mild/moderate periodontitis were selected. Two sites in each individual were sequentially sampled using either the deep-intracrevicular or orifice technique. Spectrophotometrically determined MPO levels were presented either as total MPO activity or MPO concentration. Although the clinical periodontal status of the 20 sampling sites were similar, the deep-intracrevicular technique regularly provided larger GCF volumes. With both techniques, the last samples contained the highest GCF volume. During sequential orifice sampling, GCF volume was relatively more stable. In general, a depletion of MPO activity was observed with sequential sampling performed with either of the techniques. Depletion of MPO did not replenish to baseline levels at the end of the 10-min sequential sampling. Although MPO activity showed a general reduction during sequential orifice sampling with both modes of data presentation, total MPO activity and MPO concentration did not match with the deep-intracrevicular technique. Due to the potential of affecting GCF volume/composition, the selection of sampling technique seems to be a critical methodological decision in GCF-profile studies, primarily during sequential sampling. In GCF-profile studies, mode of data presentation should also be considered.     

Effects of tadalafil on ischemia/reperfusion injury in rat brain

Cerebral ischemia–reperfusion (I/R) injury is caused by lack of blood supply to the brain. The accumulation of toxic products such as reactive oxygen species (ROS) occurs on reperfusion, when the occlusion is removed. The resulting oxidative stress results in the initiation of pathways leading to necrotic and apoptotic cell death. Tadalafil (TAD) prevents the accumulation of ROS and increases antioxidant cellular protective mechanisms. The aim of this study was to investigate the effect of TAD treatment against short-term global brain I/R injury in rats. The study was carried out on 30 Wistar-albino rats, which were divided into three groups including a control group (n = 10), an I/R group (n = 10) and an I/R + TAD group (n = 10) (2 mg/kg/day for 4 days before ischemia). At the end of the experiment, tissue samples were collected for both biochemical and histopathological analyses. Malondialdehyde was significantly lower in the TAD-administered group (9.06 ± 0.15) than in the I/R group (p < 0.05). However, no significant difference was observed in nitric oxide levels in the TAD-administered group compared to the I/R group. The mean superoxide dismutase level was significantly higher in the I/R–TAD group than the I/R group. There was no statistically significant difference in glutathione peroxidase levels in I/R + TAD group compared to I/R group. Histopathologically, TAD-administered group provided significant morphological improvement compared to the I/R group. We concluded that TAD prevented I/R-induced neurotoxicity as shown by obtained biochemical and histopathological findings.     

Plasma homocysteine levels in living kidney donors before and after uninephrectomy

An increased prevalence of hyperhomocysteinemia has been observed among patients with end-stage renal disease, and numerous studies have demonstrated that kidney function is one of the most important determinants of plasma total homocysteine (tHcy) concentration. In an effort to understand the mechanism of hyperhomocysteinemia in renal disease, we chose, as our model, living kidney donors who had undergone uninephrectomy. We studied 10 living kidney donors and measured fasting plasma tHcy, plasma creatinine, folate, vitamins B(12) and B(6), and high-sensitivity C-reactive protein (hsCRP) 24 hours before nephrectomy and 2 days, 6 weeks, and 6 months after nephrectomy compared to the values 24 hours before nephrectomy. Mean fasting tHcy and creatinine concentrations were significantly higher in donors 2 days, 6 weeks and 6 months after nephrectomy they were 24 hours before nephrectomy. Both the increases in tHcy levels 2 days after nephrectomy and subsequent decreases 6 weeks and 6 months after are paralleled by the changes in plasma creatinine values, although neither returned to its presurgery value. Decreases in tHcy are significantly correlated with decreases in creatinine values. The B vitamins were unchanged, and the hsCRP level was increased 2 days after surgery but had returned to the baseline level after 6 weeks. We conclude that tHcy and creatinine levels parallel each other after uninephrectomy and that the gradual decrease in tHcy is accounted for by hypertrophy of the remaining kidney. Our results, the first to be obtained from living kidney donors, support the hypothesis that renal metabolism of tHcy is the mechanism responsible for the correlation between renal function and plasma tHcy level.     

Antagonist activity of the antipsychotic drug lithium chloride and the antileukemic drug imatinib mesylate during glioblastoma treatment in vitro

Objectives: Glioblastoma (GBM), the most common primary tumour of the central nervous system, is characterised by a high malignancy and poor prognosis. The aims of this study were to investigate whether the combination of imatinib mesylate (IM) and lithium chloride (LiCl) exhibited a synergistic effect in treatment and to determine whether midkine (MK) affected the fate of this treatment in vitro.

Methods: Monolayer and spheroid cultures of the T98G human GBM cell line were treated with an IM and LiCl combination for 72 h. The cell proliferation index, apoptotic index, cell cycle distribution, apoptotic and anti-apoptotic protein levels, and cAMP level as well as the cellular morphology and ultrastructure were evaluated.

Results: All applications inhibited cell proliferation and induced apoptosis. The most substantial decreases in cell proliferation and the caspase-3, epidermal growth factor receptor (EGFR), platelet derived growth factor receptor-alpha (PDGFR-α), multidrug resistance protein-1 (MRP-1), aquaporin-4 (AQP-4) and cAMP levels were induced by the LiCl treatment, which exhibited more pronounced effects compared with the combination treatment. LiCl was less effective in decreasing the MK and B cell lymphoma-2 (Bcl-2) levels compared with the combination treatment. The most substantial decrease in the p170 levels was identified following the combination treatment, whereas IM induced the second greatest decrease. LiCl alone had no effect on the p170 levels. IM induced the most substantial decrease in the phospho-glycogen synthase kinase 3-beta (p-GSK-3β)/glycogen synthase kinase 3-beta (GSK-3β) ratio, and LiCl induced the second most substantial decrease. Both LiCl and the combination treatment induced G2 + M arrest, whereas IM induced G0 + G1 arrest after 72 h of exposure. An apoptotic appearance and autophagic vacuoles were commonly identified in the LiCl, combination and IM groups, respectively.

Conclusions: The combination of IM and LiCl exhibited an antagonist effect, and MK had a role at this antagonism.