The future potential of eicosanoids and their inhibitors in paediatric practice

Association of thromboxane A2 receptor gene polymorphisms with cerebral infarction in a Chinese population

Platelet aggregation is crucial for the development of cerebral infarction (CI) and it is markedly increased due to the binding of thromboxane A2 (TXA2) to its receptor (TXA2R). Therefore, TXA2R plays a central role in the pathogenesis of atherosclerosis and thrombosis. This study aimed to investigate the relationship between human TXA2R gene single nucleotide polymorphisms (SNPs) and non-cardiogenic CI in a Chinese cohort. Two SNPs, rs768963 and rs4523, located in the regulatory and coding regions of TXA2R gene, respectively, were examined in DNA samples from 407 Chinese patients with CI and 270 controls. 407 CI was categorized into subtypes using Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. There was no significant association between rs4523 variants and CI. However, there was a significant difference in the overall distribution of genotypes and dominant/recessive models of rs768963 between CI and control groups. In addition, multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with total CI (P = 0.023), large artery atherosclerosis subtype (P = 0.009), small artery occlusion subtype (P = 0.044) after adjusting for confounding factors (odds ratio = 1.533, 1.918 and 1.573, respectively). We conclude that TXA2R rs768963 polymorphism is associated with CI in a Chinese population.

Emerging targets in lipid-based therapy

The use of prostaglandins and NSAIDS in the clinic has proven that lipid mediators and their associated pathways make attractive therapeutic targets. When contemplating therapies involving lipid pathways, several basic agents come to mind. There are the enzymes and accessory proteins that lead to the metabolism of lipid substrates, provided through diet or through actions of lipases, the subsequent lipid products, and finally the lipid sensors or receptors. There is abundant evidence that molecules along this lipid continuum can serve as prognostic and diagnostic indicators and are in fact viable therapeutic targets. Furthermore, lipids themselves can be used as therapeutics. Despite this, the vernacular dialog pertaining to "biomarkers" does not routinely include mention of lipids, though this is rapidly changing. Collectively these agents are becoming more appreciated for their respective roles in diverse disease processes from cancer to preterm labor and are receiving their due appreciation after decades of ground work in the lipid field. By relating examples of disease processes that result from dysfunction along the lipid continuum, as well as examples of lipid therapies and emerging technologies, this review is meant to inspire further reading and discovery.

Effect of YM158, a dual lipid mediator antagonist, on immediate and late asthmatic responses, and on airway hyper-responsiveness in guinea pigs

The effects of lipid mediator antagonists: the LTD4-receptor antagonist pranlukast, the TXA2-receptor antagonist seratrodast, and the novel dual LTD4- and TXA2-receptor antagonist YM158 (3-[(4-tert-butylthiazol-2-yl)methoxy]-5'-[3-(4-chlorobenzenesu lfonyl) propyl]-2'-(1H-tetrazol-5-ylmethoxy)benzanilide monosodium salt monohydrate) were investigated in animals exhibiting immediate asthmatic response (IAR), late asthmatic response (LAR) and airway hyper-responsiveness (AHR). Antigen-induced LAR and AfR are inhibited by orally administered pranlukast (30, 100 mg/kg) and seratrodast (3, 10 mg/kg). YM158 (30 mg/kg), orally administered before or after IAR induction, also inhibited both LAR and AHR. However, while the inhibitory effects of pranlukast and seratrodast on IAR were marginal, the effects of YM158 (3, 10, 30 mg/kg) were dose-dependent, probably due to its multiple sites of action. Additionally, orally administered YM158 (30 mg/kg) inhibited ozone-induced AHR in guinea pigs. Thus, an antagonist that inhibits several lipid mediators might exhibit greater efficacy in treating asthmatic responses than antagonists with a single site of action. Therefore, YM158 shows great promise as a drug that will be able to treat bronchial asthma and related disorders more potently than currently used single-pathway inhibitors.

Novel immunomodulators for topical skin disease therapy

The use of topical corticosteroids has revolutionised the treatment of inflammatory skin diseases. However, problems including pharmacological resistance, as well as the side effect profile of potent topical corticosteroids, has prompted studies to investigate into other topical non-corticosteroidal agents in inflammatory skin diseases. This review outlines the major types of inflammatory skin diseases and discusses emerging therapies based on topical immunosuppressive macrolide antibiotics. In particular, tacrolimus and ascomycin derivatives have been shown to be effective for treating atopic dermatitis with a surprising lack of side effects. It is expected that these agents will play an important role in future dermatological therapy. Accumulating evidence suggests the importance of lipid-derived mediators of inflammation (eicosanoids and platelet-activating factor) in cutaneous inflammatory diseases. The role of these mediators in skin inflammation is also addressed in this review. Though there appears to be a large amount of redundancy in the activities of these lipid mediators, this family of agents could potentially serve as targets for anti-inflammatory therapy. Inasmuch as the phospholipase A(2) family of enzymes serve to synthesise both eicosanoids and platelet-activating factor, inhibition at this step could have important therapeutic benefits in designing therapy for inflammatory skin diseases.

Successful cerebral artery stent placement for total occlusion of the vertebrobasilar artery in a patient suffering from acute stroke. Case report

A 64-year-old man suffering from crescendo brainstem symptoms due to acute total occlusion of the vertebrobasilar artery was successfully treated by cerebral artery stent placement. The total occlusion of a long segment of the vertebrobasilar artery was completely recanalized by implanting two flexible, balloon-expandable coronary stents. The patient's clinical outcome 30 days later was favorable. No complications occurred during or after the procedure. This therapeutic option may prove to be a useful means to revascularize an acute total occlusion of the vertebrobasilar artery.