Induction of the Conversion of Xanthine Dehydrogenase to Oxidase in Rabbit Liver by Cu2+, Zn2+ and Selenium Ions

Abstract— Effects of Cu²⁺, Zn²⁺, Fe²⁺ and selenium ions on the conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Under basal conditions, xanthine oxidase activity represented only 16% of the total xanthine oxidase plus dehydrogenase activity. Cu²⁺ (2–10 μm ), Zn²⁺ (5–30 μm ) and selenium ions (5–100 μm ) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. The concentrations of Cu²⁺, Zn²⁺ and selenium ions required for increasing xanthine oxidase activity by 50% was approximately 4, 10 and 20 μm , respectively. On the other hand, Fe²⁺ had no effect on the conversion of the enzyme up to 100 μm . These results suggest that Cu²⁺, Zn²⁺ and selenium ions have the potential to modulate the conversion of xanthine dehydrogenase to oxidase in rabbit liver.     

Laparoscopic adrenalectomy in patients with large adrenal tumors

OBJECTIVES: The maximum size of adrenal tumors that should be removed by laparoscopic adrenalectomy is controversial. We conducted a retrospective comparison of the results of laparoscopic adrenalectomy between patients with adrenal tumors > or =6 cm ('large tumors') and patients with adrenal tumors <6 cm ('small tumors'). METHODS: The participants in the study were 16 patients with large tumors and 111 patients with small tumors. The patients comprised 59 men and 68 women (mean age, 49.0 years; age range, 23-79) with varying diagnoses. Of the 16 patients with large tumors, five had Cushing's syndrome, four had pheochromocytomas, six had a non-functional tumor and one had malignant lymphoma. Adrenal tumors were confirmed by hormonal assays, biochemical tests and computed tomography. Of the 16 large tumors, five tumors were on the right and 11 were on the left. RESULTS: We found no significant differences in general demographic parameters between patients with large and small tumors. The mean duration of surgery was not significantly different between two groups. (large tumors, 210 min; small tumors,175 min). The mean volume of blood loss was 212 mL for large tumors and 30 mL for small tumors (P < 0.001, significant difference). There was no significant difference in time until walking, duration of hospitalization or number of using analgesics used. The time to first oral intake of group 1 (<6 cm) was significantly shorter than group 2 (> or =6 cm). Tumor size (> or =7.5 cm) was an independent predictor of a longer operation and greater blood loss in large tumors. CONCLUSIONS: Laparoscopic adrenalectomy for large tumors was safe and minimally invasive.     

ISOLATION AND PHENOGENETICS OF A NOVEL CIRCADIAN RHYTHM MUTANT IN ZEBRAFISH

Widespread use of zebrafish (Danio rerio) in genetic analysis of embryonic development has led to rapid advances in the technology required to generate, map and clone mutated genes. To identify genes involved in the generation and regulation of vertebrate circadian rhythmicity, we screened for dominant mutations that affect the circadian periodicity of larval zebrafish locomotor behavior. In a screen of 6,500 genomes, we recovered 8 homozygous viable, semi-dominant mutants, and describe one of them here. The circadian period of the lager and lime (lag^dg2) mutant is shortened by 0.7 h in heterozygotes, and 1.3 h in homozygotes. This mutation also shortens the period of the melatonin production rhythm measured from cultured pineal glands, indicating that the mutant gene product affects circadian rhythmicity at the tissue level, as well as at the behavioral level. This mutation also alters the sensitivity of pineal circadian period to temperature, but does not affect phase shifting responses to light. Linkage mapping with microsatellite markers indicates that the lag mutation is on chromosome 7. A zebrafish homolog of period1 (per1) is the only known clock gene homolog that maps near the lag locus. However, all sequence variants found in per1 cDNA from lag^dg2 mutants are also present in wild type lines, and we were unable to detect any defect in per1 mRNA splicing, so this mutation may identify a novel clock gene.     

Reliability of the task-related component (P3b) of P3 event-related potentials

Abstract Within session and between session reliabilities of the task-related component (P3b) of the P3 measures (amplitude, area and latency) and their habituation across eight sessions separated by 7–10 days, except for an interval of 1 month between the 6th and 7th sessions, were studied based on the difference waves, which were obtained by subtracting the ignored infrequent event-related potentials (ERP) from the target ERP elicited by a standard auditory oddball paradigm with eyes-open or eyes-closed conditions in 10 normal subjects. The within session reliabilities represented as Pearson correlation coefficients ( r ) were 0.57-0.66 for the three measures except for those for the latency and amplitude under the eyes-closed condition. The between session reliabilities expressed as intraclass correlation coefficients ( R ) ranged from 0.54 to 0.60 except for that for latency under eyes-closed conditions. Long-term habituation occurred within the first six sessions for the P3b amplitude and area, and dishabituation took place in the 7th session after an interval of 1 month, whereas no such phenomenon was observed for the P3b latency. Implications of the present results are discussed in terms of the clinical application of the P3 measures.