Synthesis,Physicochemical Properties,and Cytotoxicity of a Series of 5′-Ester Prodrugs of 5-Iodo-2′-deoxyuridine

Five aliphatic 5-esters of 5-iodo-2deoxyuridine (IDU) were synthesized via an acid chloride alcoholysis reaction. The solubility in pH 7.4 phosphate buffer, lipophilicity as determined by partition experiments in octanol/pH 7.4 buffer, and cytotoxicity of these potential prodrugs were evaluated. The esters showed a 43- to 250-fold increase in lipophilicity and a 1.6- to 14-fold decrease in aqueous solubility relative to IDU. At a concentration of 50 µM, all esters showed reduced cytotoxicity toward uninfected Vero cells relative to IDU.     

Prodrugs of 5-Iodo-2′-Deoxyuridine for Enhanced Ocular Transport

Problems associated with the use of 5-iodo-2-deoxyundine (IDU) in the treatment of herpes simplex keratitis can be attributed largely to the polar nature of IDU resulting in its poor permeability across the lipoidal epithelial layer of the corneal membrane. Five aliphatic 5-esters of IDU were synthesized and evaluated as prodrugs for potential use in the treatment of deep ocular infections such as stromal keratitis, iritis, and even retinitis. A parabolic relationship between in vitro corneal membrane permeability and carbon chain length of prodrugs is evident. For a given prodrug, enzymatic hydrolysis proceeded most readily in iris–ciliary body, followed by cornea and aqueous humor. An increase in carbon chain length made the prodrugs more enzymatically labile but more resistant to chemical hydrolysis at pH 7.4 and 34°C. The 5-butyryl ester of IDU exhibited an approximately fourfold increase in aqueous humor IDU concentration relative to IDU at 25 min following instillation of 25-µl 5 mM solutions.     

Studies with {α 2}-adrenoceptor agonists and alcohol abstinence syndrome in rats

Various ₂-adrenoceptor agonists were assessed for their effects on alcohol abstinence syndrome in rats. In the first experimental model, groups of Wistar rats were made alcohol dependent by feeding alcohol together with sweetened milk for 15 days. The volume of fluid intake was measured every 12 h to determine daily ethanol consumption. Abstinence signs following abrupt alcohol withdrawal were observed in control as well as test groups receiving various ₂-adrenoceptor agonists. Clonidine, guanfacine and B-HT 920, in equimolar concentration (0.5 M/kg), effectively attenuated the various abstinence signs, which developed after alcohol withdrawal. In the other experimental model, rats were subjected to cold water immersion to induce wet shakes. The inhibitory action of ₂-adrenoceptor agonists was assessed in this test model. Clonidine, guanfacine and B-HT 920 markedly suppressed the cold water immersion-induced wet shakes and pretreatment with yohimbine (0.1 and 2.0 M/kg) reversed this inhibitory effect. The present data reveal the possible therapeutic potential of ₂-adrenoceptor agonists in alleviating alcohol abstinence syndrome, and suggest that the resultant reduced noradrenergic activity may be responsible for the beneficial action.     

Statin-Associated Polymyositis Following Omeprazole Treatment

Statins are an extensively used class of drugs, and myopathy is an uncommon, but well-described side effect of statin therapy. Inflammatory myopathies, including polymyositis, dermatomyositis, and necrotizing autoimmune myopathy, are even more rare, but debilitating, side effects of statin therapy that are characterized by the persistence of symptoms even after discontinuation of the drug. It is important to differentiate statin-associated inflammatory myopathies from other self-limited myopathies, as the disease often requires multiple immunosuppressive therapies. Drug interactions increase the risk of statin-associated toxic myopathy, but no risk factors for statin-associated inflammatory myopathies have been established. Here we describe the case of a man, age 59 years, who had been treated with a combination of atorvastatin and gemfibrozil for approximately 5 years and developed polymyositis after treatment with omeprazole for 7 months. Symptoms did not resolve after discontinuation of the atorvastatin, gemfibrozil, and omeprazole. The patient was treated with prednisone and methotrexate followed by intravenous immunoglobulin, which resulted in normalization of creatinine kinase levels and resolution of symptoms after 14 weeks. It is unclear if polymyositis was triggered by interaction of the statin with omeprazole and/or gemfibrozil, or if it developed secondary to long-term use of atorvastatin only.     

Selenium reducing Citrobacter fruendii strain KP6 from Mandovi estuary and its potential application in selenium nanoparticle synthesis

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - The present study foregrounds the isolation of selenium tolerant bacteria from Mandovi estuary of Goa, India,...     

Incidence and predictors of de novo late-onset persistent atrial fibrillation in postoperative rheumatic heart disease patients (LOAF-RHD study)

Journal of Interventional Cardiac Electrophysiology - Late-onset atrial fibrillation (LOAF) after valve surgery for degenerative mitral valve disease often with underlying mitral valve prolapse is...     

Anti-viral immune responses in a primitive lung: Characterization and expression analysis of interferon-inducible immunoproteasome subunits LMP2, LMP7 and MECL-1 in a sarcopterygian fish,the Nigerian spotted lungfish (Protopterus dolloi)

Lungfishes (Dipnoi) represent the closest ancestor of tetrapods. Dipnoi have dual breathing modes extracting oxygen from water and air. The primitive lungs of lungfishes are exposed to external antigens including viruses. To date, the immune response of lungfishes against viruses has not been investigated. During viral immune responses, cell exposure to type I interferon induces the replacement of the constitutive proteasome with LMP2, LMP7 and MECL-1 beta subunits forming the immunoproteasome and enhancing antigen presentation to MHC class I molecules. In order to study the immune defense system of the lungfish lung, we have characterized for the first time the three immunoproteasome subunits in the sarcopterygian fish, the Nigerian spotted lungfish (Protopterus dolloi). LMP2, LMP7 and MECL-1 were identified in P. dolloi and their sequences encoded predicted proteins of 216, 275 and 278 amino acids, respectively. The mRNA of these three genes was expressed in multiple tissues, including the lung, with the highest abundance observed in kidney and post-pyloric spleen. In vitro stimulation of lungfish lung and kidney primary cell cultures with PolyI:C for 4 and 12 h resulted in increased LMP2, LMP7 and MECL-1 expression in both tissues. These results suggest a central role of these genes in the activation of an antiviral immune response in lungfish. Importantly, they indicate that the primitive lung of the common ancestor of all tetrapods is capable of inducing the expression of these genes in response to viral stimulation.