Glycosphingolipids are major components of the membrane raft, and several kinds of viruses and bacterial toxins are known to bind to glycosphingolipids in the membrane raft. Since the viral genes and pathogenic proteins that are taken into cells are directly delivered to their target organelles, caveolae/raft-mediated endocytosis represents a promising pathway for specific delivery. In the present study, we demonstrated the ability of an artificial pentadecapeptide, which binds to ganglioside GM3, to deliver protein into cells by caveolae/raft-mediated endocytosis. The cellular uptake of a biotinylated GM3-binding peptide (GM3BP)-avidin complex into HeLa cells was observed, and the cellular uptake of this complex was inhibited by an incubation with sialic acid or endocytic inhibitors such as methyl-ß-cyclodextrin, and also by an incubation at 4 °C. These results indicate that the GM3BP-avidin complex bind to GM3 in membrane raft, and are taken into cell through caveolae/raft-mediated endocytosis. The GM3BP-avidin complex was transported into cells and localized around the nucleus more slowly than a human immunodeficiency virus type 1 TAT peptide. Furthermore, the uptake of a green fluorescent protein (GFP) linked with GM3BP into HeLa cells was similar to that of the GM3BP-avidin complex, and the localization of the GM3BP-GFP fusion protein was markedly different with that of the TAT-GFP fusion protein. The uptake and trafficking of GM3BP were distinguished from conventional cell-penetrating peptides. GM3BP has potential as a novel peptide for the selective delivery of therapeutic proteins and materials into cells in addition to being a cell-penetrating peptide.

A significant proportion of patients with unipolar depression clinically develop manic or hypomanic switch during acute antidepressant treatment. Elucidation of its prevalence and predicting factors is of clinical relevance during acute antidepressant treatment of such patients. We retrospectively studied patients with unipolar depression who were admitted to our department during the 6-year period from 1997 to 2002 and who had fewer than 3 previous episodes before admission. The clinical background of the consecutive patients with manic/hypomanic switch (n = 37) who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria was compared with that of patients without manic/hypomanic switch (n = 245). The prevalence rate of manic/hypomanic switch was 13.1%. The switch group was composed of 23 men and 14 women, whose average age was 48.8 +/- 12.3 years (range, 26-78 years). Manic/hypomanic switch was most frequently observed between 2 and 3 weeks after the antidepressant was increased to the ongoing dose. Antidepressants were decreased in 13 patients and discontinued in 23. Manic/hypomanic episodes lasted from 1 to 8 weeks. The patients in the switch group included a greater proportion of male subjects and had a higher frequency of family history of bipolar disorders than those in the nonswitch group. The mean doses of antidepressants were not significantly different between these groups. The higher frequency of manic/hypomanic switch occurring around the period when antidepressants begin to show clinical effects and the higher frequency of family history of bipolar disorders might suggest a biological susceptibility to antidepressants in patients of the switch group.

Arachidonic acid (AA) is metabolized to epoxyeicosatrienoic acids (EETs) via cytochrome enzymes such as CYP 2C9, 2C8 and 2J2. EETs play a role in cardioprotection and regulation of blood pressure. Recently, adverse reactions such as sudden heart attack and fatal myocardial infarction were reported among patients taking angiotensin II receptor blockers (ARBs). As some ARBs have affinity for these CYP enzymes, metabolic inhibition of AA by ARBs is a possible cause for the increase in cardiovascular events. In this study, we quantitatively investigated the inhibitory effects of ARBs on the formation of EETs and further metabolites, dihydroxyeicosatrienoic acids (DHETs), from AA via CYP2C8. In incubations with recombinant CYP2C8 in vitro, the inhibitory effects were compared by measuring EETs and DHETs by HPLC-MS/MS. Inhibition of AA metabolism by ARBs was detected in a concentration-dependent manner with IC 50 values of losartan (42.7 µM), telmisartan (49.5 µM), irbesartan (55.6 µM), olmesartan (66.2 µM), candesartan (108 µM), and valsartan (279 µM). Losartan, telmisartan and irbesartan, which reportedly accumulate in the liver and kidneys, have stronger inhibitory effects than other ARBs. The lower concentration of EETs leads to less protective action on the cardiovascular system and a higher incidence of adverse effects such as sudden heart attack and myocardial infarction in patients taking ARBs.Key words epoxyeicosatrienoic acid; arachidonic acid; drug-endogenous interaction; angiotensin II receptor blocker; dihydroxyeicosatrienoic acid Arachidonic acid (AA), a component of the cell membrane, is known to be metabolized to prostaglandins, thromboxaneA 2 , leukotrienes and other bioactive substances 1) (Fig. 1). AA is also metabolized to epoxyeicosatrienoic acids (EETs) via cytochrome P450 isoforms such as CYP 2C9, 2C8 and 2J2, and is further converted to the corresponding dihydroxyeicosatrienoic acids (DHETs) by soluble epoxide hydrolase (sEH).2-7) There are four structural isomers, 14,15-, 11,12-, 8,9-and 5,6-EET, that are reported to have vasodilatory and anti-inflammatory effects, while endothelium-derived hyperpolarizing factor (EDHF) action has been reported for 14,15-, 11,12-EET, [8][9][10][11][12] preconditioning effects have been reported for 14,15-EET, 13) and blood pressure regulating effects have been reported for 11,12-EET. 14)Totah and Rettie reported that CYP2C8, which constitutes about 7% of total microsomal CYP content in the human liver, appears to be important for metabolizing AA.15) CYP2C8 mainly generates 14,15-, 11,12-EET from AA, and the ratio of 14,15-EET : 11,12-EET is reported to be 1.25 : 1. 11) These results suggest that cardiovascular events such as hypertension and myocardial infarction are caused by decreased concentrations of these EETs.Angiotensin II receptor blockers (ARBs) are used for hypertensive patients with diabetes because of their cardio-and renoprotective effects. However, effects of ARBs other than the lowering of hypertension have recently been reported. 16)In a meta-a...

Universities and colleges seek to help all students succeed. However, foreign graduate students experience a different set of challenges than domestic students. Culture shock and writing in a foreign language are just a few examples that threaten their overall success. This qualitative participatory action research study describes and explains how two graduate students and a faculty mentor engaged in mentoring and structured reflective writing activities designed to address these challenges. The research data include a focus group interview, analysis of selected journal pages and conference presentations. Results indicate that reflective journal writing and mentoring help foreign graduate students de-stress, learn the tacit knowledge of the academy and participate in scholarly activities like conference presentations and publishing.

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