Is the High Proportion of Males in a Population of the Self-Incompatible Fraxinus platypoda (Oleaceae) Indicative of True Androdioecy or Cryptic-Dioecy?

Androdioecy is a rare reproductive system. Fraxinus platypoda, a woody canopy species in Japan's mountainous riparian zones, is described as a morphologically androdioecious species. In this study, we tried to detect whether F. platypoda is also functionally androdioecious. We analyzed its sexual expression, seed development, pollen morphology and germination ability, pollination systems, and mast flowering behavior. We found that the hermaphrodite trees are andromonoecious, with inflorescences bearing male and hermaphroditic flowers, whereas male individuals had only male flowers. Pollen morphology was identical in male flowers, in hermaphrodite flowers of an andromonoecious individual, and in male flowers of male individuals. Pollen from both types of individuals was capable of germination both ex vivo (on nutrient medium) and in vivo in pollination experiments. However, compared with pollen from andromonoecious trees, pollen from male trees showed a higher germination rate. The self-pollination rate of bagged hermaphroditic flowers was almost zero. The fruit set rate following cross-pollination with male pollen from a male tree was higher than that following natural pollination, whereas the rate with hermaphroditic pollen was the same. The flowering and fruiting of F. platypoda have fluctuated over 17 years; the flowering of the two types of sexual individuals exhibited clear synchronization during this period. The frequency of male individuals within the populations is 50%. The maintenance of such a proportion of males in populations of the self-incompatible F. platypoda is either indicative of a true androdioecious species with a diallelic self-incompatibility system or a cryptic-dioecious species. This alternative is discussed here.

Newly developed signal-averaged vector-projected 187-channel electrocardiogram can evaluate the spatial distribution of repolarization heterogeneity.

The purpose of this study was to verify the spatial distribution of myocardial repolarization heterogeneity using a newly developed 187-channel signal-averaged vector-projected ECG (187-ch SAVP-ECG). We constructed corrected recovery time (RTc) and Tpeak-end (corrected Tp-e) dispersion maps using a 187-ch SAVP-ECG based on vector-projection theory using a Mason-Likar lead system. We compared the spatial distribution and quantitative values of dispersion maps by 187-ch SAVP-ECG with those by 64-ch magnetocardiography (MCG) in 27 normal controls (control) and 16 patients (12 myocardial infarction (MI), and 4 dilated cardiomyopathy (DCM)). The wave pattern of the 187-ch SAVP-ECG in the representative cases was similar to those in 64-ch MCG. Spatial distribution increased RTc and corrected Tp-e dispersion maps defined by 187-ch SAVP-ECG were in agreement with those by 64-ch MCG. The value of RTc dispersion in MI was higher than that in control (41 +/- 21 ms in MI versus 30 +/- 12 ms in control, P < 0.05). The value of corrected Tp-e dispersion in DCM was higher than that in control (58 +/- 12 ms in DCM versus 30 +/- 13 ms in control, P < 0.001). There was a good correlation between RTc and corrected Tp-e dispersion values determined by 187-ch SAVP-ECG and 64-ch MCG modalities (y = 0.46x + 18, r = 0.62, P = 0.02 for RTc dispersion; y = 0.52x + 15, r = 0.63, P = 0.01 for corrected Tp-e dispersion). RTc and corrected Tp-e dispersion maps by 187-ch SAVP-ECG based on vector-projection theory can evaluate the spatial distribution of myocardial repolarization heterogeneity.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone: a report on two cases.

BACKGROUND: Amiodarone is an effective antiarrhythmic agent for life-threatening arrhythmias but has some noncardiac toxicity. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by amiodarone during long-term therapy seems to be rare among adverse effects. SUBJECTS AND RESULTS: We report on two elderly cases that developed hyponatremia caused by SIADH occurring during the initial loading period of amiodarone therapy. Both cases improved within 3 weeks after reduction of the dose, although amiodarone was continued. CONCLUSIONS: Amiodarone-induced SIADH may occur during the initial loading period, and it may be improved by reduction of the dose without discontinuation of the drug.