Department of Periodontics, Government Dental College and Research Institute, Bangalore, India.
Background: Leukotriene B4 (LTB4) is a membrane-derived lipid mediator formed from arachidonic acid. LTB4 is among the most potent stimulants of polymorphonuclear leukocytes (PMNs) and, thus, participates in tissue injury by recruiting PMNs in a pathophysiologic scenario of periodontal and other systemic diseases. The aim of the present study was to assess the relationship between clinical parameters and concentrations of LTB4 within gingival crevicular fluid (GCF) from inflamed gingiva and periodontitis sites before and after the treatment of periodontitis.
Methods: Sixty subjects were divided into three groups with 20 subjects in each group: healthy (group 1), gingivitis (group 2), and chronic periodontitis (group 3). Groups were based on periodontal disease index (PDI), clinical attachment loss (CAL), and radiographic evidence of bone loss. Group 4 consisted of the subjects in group 3 at 6 to 8 weeks after treatment, i.e., scaling and root planing (SRP). GCF samples collected from each patient were quantified for LTB4 using an enzymatic immunometric assay. In addition, the correlation between in situ LTB4 levels and clinical parameters was analyzed in each group.
Results: The highest mean LTB4 concentration in GCF was observed in group 3 (185.2 pg/microl), and the lowest was observed in group 1 (39.6 pg/microl). Its level in group 3 decreased to 79.35 pg/microl after treatment (group 4). Further, GCF LTB4 levels in all groups showed a statistically significant positive correlation with PDI and CAL (P <0.005).
Conclusion: The substantial increase in GCF LTB4 concentrations with the severity of periodontal disease and a concomitant decrease in its level following SRP in subjects with periodontitis suggest a possible role for LTB4 as a biomarker in the progression of periodontal disease and aid in our understanding of the pathogenesis and the appropriate treatment of periodontal diseases by utilization of LTB4 inhibitors and antagonists to LTB4 receptor as “magic bullet” that would bypass the need for professional and self-administered oral prophylaxis protocols.
Cell-specific delivery of kinase inhibitors using lysozyme: A novel approach to treat renal fibrosis PRAKASH J1, KOK RJ1, VAN GOOR H2, POELSTRA K1 1University of Groningen, The Netherlands; 2University Medical Centre Groningen, The Netherlands.
Background: Activation of renal tubular cells, mediated by several kinase pathways, is the key process in renal fibrosis. However, kinase enzymes regulate many normal physiological processes elsewhere. Therefore we developed a novel strategy to deliver kinase inhibitors selectively to renal tubular cells using lysozyme (LZM) as a drug carrier protein. This will increase therapeutic drug levels in target cells and reduce side-effects. Aim: 1) To deliver different kinase inhibitors, that is, p38 MAPK inhibitor SB202190, TGF-beta kinase inihibitor (TKI) and RhoA kinase inhibitor Y27632 to tubular cells using LZM. 2) To evaluate the efficacy of drug-LZM conjugates in renal fibrosis models in rats.
Methods: SB202190, TKI and Y27632 were conjugated to LZM using ULS™ linker. Drug-LZM conjugates were characterized for drug to protein ratio and stability in many matrixes using HPLC methods. The renal uptake of the conjugates was studied upto 72h after a single i.v. injection in rats using HPLC methods. The efficacy of the conjugates was examined in either unilateral ureteral obstruction model (UUO) or ischemia/reperfusion injury model (I/R) in rats. The antifibrotic effects were determined using RT-PCR and immunohistochemical techniques.
Results: All drug-LZM conjugates contained 1:1 drug to protein ratio. In vitro, the conjugates released drugs in kidney homogenates while remained stable in serum and buffers. In vivo, the conjugates were rapidly accumulated in renal tubular cells and slowly released their drug intracellularly upto 72h after a single i.v. injection. Treatment with TKI-LZM and SB-LZM reduced renal fibrotic markers in rats with UUO and I/R injury, respectively. Intriguingly, blockade of RhoA kinase pathway with Y27632-LZM in kidneys substantially inhibited I/R-induced inflammatory and fibrotic processes. Moreover, Y27632-LZM attenuated the transdifferentiation of tubular cells, a crucial process after renal injury.
Conclusions: 1) We have successfully delivered several kinase inhibitors selectively to tubular cells in kidneys using our novel strategy. 2) Drug-LZM rapidly deposited in the cells and released the active drug intracellularly for prolonged time. 3) Targeted conjugates significantly inhibited renal inflammation and fibrosis in different animal models.
Valproic Acid (VA) May Be Effective in the Treatment of Headaches Associated with Reactivation of Cerebral Toxoplasmosis (CT)
PRANDOTA J
Dpt of Social Pediatrics, University Medical School, Wroclaw, Poland
Background: Valproic acid (VA) is effective in the treatment and prophylaxis of migraine with and without aura, refractory migraine headache, drug-resistant migraine, tension-type headache, chronic daily headache, and convulsive disorders. We found that different types of headaches were precipitated by various diseases or medications probably because marked immune irregularities associated with these events caused reactivation of CT. The aim of this study was to focus on pathomechanisms that may be responsible for these clinical effects.
Methods: Literature data were selected to illustrate that latent CNS T. gondii infection/ inflammation intensity and/or host defense mechanisms may be affected by changes in production of NO, cytokines, tryptophan degradation by indoleamine 2,3-dioxygenase, limiting the availability of intracellular iron to T. gondii, production of reactive oxygen/nitrogen species, mechanisms mediated by an IFN- responsive gene family, and finally cause reactivation of CT. It must be added that cytosolic calcium T. gondii tachyzoite levels.play an important role in their invasion to the host cells and intracellular replication.
Results: VA was found to induce generation of IL-1, IL-1, IFN-, IL-6, ROS, NO, and monocyte attractant protein-1. These irregularities could markedly affect both the host and T. gondii defense mechanisms important for immune control of the parasite, because the in vitro study showed that VA inhibited replication of tachyzoites at median concentration of 4.1 g/ml, similar to that of trimethoprim (5,3 g/ml). In addition, trimethoprim exerted a synergistic effect with VA which may suggest that the mechanisms of actions of these two drugs were different. This suggestion may be supported by the finding that VA is also capable of inhibiting calcium transport through cellular ion channels. Because VA brain levels in the epileptic patients are about 20% of serum concentrations, and it is known that the subjects with schizophrenia and bipolar disorder who orally receive VA therapy achieve its blood concentrations of 50-100 g/ml, the drug may be effective also in treatment of CT.
Conclusion: VA may be effective in the treatment of CT, various types of headaches and convulsive disorders because it affects both the immune state of the host and/or the parasite, and decreases calcium ion available for T. gondii tachyzoites, important for their motility.
