Novel antioxidative metabolites in rat liver with ingested sesamin

Sesamin, a major lignan in sesame oil, is known to have many biological activities, especially protective effects against oxidative damage in the liver. As sesamin itself has no antioxidative properties in vitro, to elucidate the mechanism of its antioxidative effects, the reaction products of sesamin in rat liver homogenate were analyzed. The methylenedioxyphenyl moiety in the structure of sesamin was shown to be changed into a dihydrophenyl (catechol) moiety. The enzymatic reaction products in vitro were identified as (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane and (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, which showed strong radical scavenging activities; the latter was a novel compound. The same metabolites were found as glucuronic acid and/or sulfic acid conjugates in substantial amounts in rat bile after oral administration of sesamin. It is suggested that sesamin is a prodrug and the metabolites containing the catechol moieties in their structures are responsible for the protective effects of sesamin against oxidative damage in the liver.     

Dating of a fault by electron spin resonance on intrafault materials

The total dose of natural radiation and the age were determined from paramagnetic defects in quartz grains at a fractured fault zone. Young age at the fault indicates that the accumulated defects in rocks were destroyed by high stress or high temperature at the time of the last fault movement, setting the clock time to zero. The technique was applied to quartz grains crushed by uniaxial compression in the laboratory to verify this interpretation.     

Protective role of ATP-sensitive potassium channels in hypoxia-induced generalized seizure

Adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channels are activated by various metabolic stresses, including hypoxia. The substantia nigra pars reticulata (SNr), the area with the highest expression of K(ATP) channels in the brain, plays a pivotal role in the control of seizures. Mutant mice lacking the Kir6.2 subunit of K(ATP) channels [knockout (KO) mice] were susceptible to generalized seizures after brief hypoxia. In normal mice, SNr neuron activity was inactivated during hypoxia by the opening of the postsynaptic K(ATP) channels, whereas in KO mice, the activity of these neurons was enhanced. K(ATP) channels exert a depressant effect on SNr neuronal activity during hypoxia and may be involved in the nigral protection mechanism against generalized seizures.     

Clip ligation for treatment of patent ductus arteriosus occlusion in three cats

Patent ductus arteriosus (PDA) is a rare congenital cardiovascular anomaly in cats. Due to their small body, intercostal thoracotomy is the most common option to close the PDA. However, few reports detail the surgical technique for ligating PDA in kittens. In this case report, three cats weighing 1.4 kg, 1.2 kg, and 2.9 kg were diagnosed PDA. Clip ligation via left fourth intercostal thoracotomy was performed and the cats were successfully treated. Postoperative echocardiography showed no residual flow in any of the cases. This case report highlights clip occlusion for small cats with PDA could be safe and effective.