Erratum to 'Head-up tilt test with clomipramine challenge in vasovagal syndrome -- a new tilt testing protocol' [Eur Heart Jnl 2003;24(7):658-659]

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Propranolol in acute migraine: a controlled study

Propranolol is an established agent in migraine prophylaxis. Uncontrolled studies have suggested an action in the acute attack. We present the first double-blind placebo controlled study of propranolol in 27 unselected patients with common (migraine without aura) and classical (migraine with aura) migraine. There were 23 pairs of headaches in the 14 patients who completed the study. No difference was found, when the data were analysed by headache pair or by patient, in severity duration and subjective assessment of efficacy between those treated in an attack with propranolol 40 mg and placebo.     

Acute nonlymphocytic leukemia complicated by severe cytophagocytosis of formed blood elements by nonmalignant histiocytes: Cause of significant clinical morbidity

A 52-year-old female presented with Philadelphia chromosome-positive acute nonlymphocytic leukemia and a morphologically benign-appearing histiocytosis with intramedullary cytophagocytosis of formed blood elements. No cause of the reactive histiocytosis could be found. Despite initial successful therapy of the acute nonlymphocytic leukemia with induction of a cytological remission, pancytopenia with marked cytophagocytosis persisted. Therapy aimed at reducing the degree of cytophagocytosis by the histiocytes, in the form of vinblastine-treated platelets and, subsequently, prednisone, was instituted. There was no significant clinical response to either therapeutic maneuver. Cytophagocytosis persisted until leukemic relapse and death ensued.     

Cluvenone induces apoptosis via a direct target in mitochondria: a possible mechanism to circumvent chemo-resistance?

The synthetic caged Garcinia xanthone, cluvenone, has potent and selective cytotoxicity against numerous cancer cell lines including those that are multi-drug resistant. The direct target of this structurally and functionally unique agent is unknown and that of the parent natural product, gambogic acid (GA), presently in clinical trials, is not yet entirely clear. For the first time, using fluorescently labeled GA (GA-Bodipy), we determined that GA-Bodipy localized in mitochondria and was effectively displaced by cluvenone in competition experiments indicating that the direct target of cluvenone resided in mitochondria and was shared by GA. In agreement with these findings, treatment of HeLa cells with cluvenone or GA resulted in disruption of mitochondrial morphology within 4 h. Furthermore, experiments using the potential sensitive JC-1 dye demonstrated that cells treated with 1 μM cluvenone for 1 h had significant loss of MMP compared to control cells. Examination of Cyt c levels in leukemia cells treated with 1 μM cluvenone resulted in a 4-fold increase in levels of both cytosolic and mitochondrial Cyt c. In agreement with Cyt c release, caspase 9 activity was increased 2.6-fold after treatment of cells for 5 h with 1 μM cluvenone. Remarkably, the caspase-9 inhibitor, Z-LEHD-FMK, blocked cluvenone-induced apoptosis in a dose-dependent manner with apoptosis being completely blocked by 10 μM of the inhibitor. In conclusion, cluvenone, an agent with potent cytotoxicity against multi-drug resistant tumor cells, has direct targets in mitochondria thus setting precedence for drug discovery efforts against these targets in the treatment of refractory cancers.