Patterns of secondary metabolite allocation to fruits and seeds in Piper reticulatum.

Little is known about the evolution, diversity, and functional significance of secondary metabolites in reproductive plant parts, particularly fruits and seeds of plants in natural ecosystems. We compared the concentration and diversity of amides among six tissue types of Piper reticulatum: leaves, roots, flowers, unripe fruit pulp, ripe fruit pulp, and seeds. This represents the first detailed description of amides in P. reticulatum, and we identified 10 major and 3 minor compounds using GC/MS and NMR analysis. We also detected 30 additional unidentified minor amide components, many of which were restricted to one or a few plant parts. Seeds had the highest concentrations and the highest diversity of amides. Fruit pulp had intermediate concentrations and diversity that decreased with ripening. Leaves and roots had intermediate concentrations, but the lowest chemical diversity. In addition, to investigate the potential importance of amide concentration and diversity in plant defense, we measured leaf herbivory and seed damage in natural populations, and examined the relationships between amide occurrence and plant damage. We found no correlations between leaf damage and amide diversity or concentration, and no correlation between seed damage and amide concentration. The only relationship we detected was a negative correlation between seed damage and amide diversity. Together, our results provide evidence that there are strong selection pressures for fruit and seed defense independent of selection in vegetative tissues, and suggest a key role for chemical diversity in fruit-frugivore interactions.

Financial incentives: alternatives to the altruistic model of organ donation.

Improvements in transplantation techniques have resulted in a demand for transplantable organs that far outpaces supply. Present efforts to secure organs use an altruistic system designed to appeal to a public that will donate organs because they are needed. Efforts to secure organs under this system have not been as successful as hoped. Many refinements to the altruistic model have been or are currently being proposed, such as "required request," "mandated choice," "routine notification," and "presumed consent." Recent calls for market approaches to organ procurement reflect growing doubts about the efficacy of these refinements. Market approaches generally use a "futures market," with benefits payable either periodically or when or if organs are procured. Lump-sum arrangements could include donations to surviving family or contributions to charities or to funeral costs. Possibilities for a periodic system of payments include reduced premiums for health or life insurance, or a reciprocity system whereby individuals who periodically reaffirm their willingness to donate are given preference if they require a transplant. Market approaches do raise serious ethical issues, including potential exploitation of the poor. Such approaches may also be effectively proscribed by the 1984 National Organ Transplant Act.

Vaginosonographic measurement of endometrial thickness in the evaluation of amenorrhea.

The progestin-induced withdrawal bleeding test has often been used in patients with amenorrhea to assess endogenous estrogen (E) production. The endometrial thickness measured by vaginal ultrasonography with a 5 MHz transducer is also dependent on E stimulation of the endometrium. In this study, 70 consecutive patients were evaluated with both the progestin-induced withdrawal bleeding test and a measurement of the endometrial thickness by vaginosonography. An endometrial thickness of 1.5 mm or less was selected to predict absence of bleeding after a progesterone (P) challenge test. This resulted in a sensitivity of 94% with a 95% confidence interval (CI) of 0.70 to 1.00 and a specificity of 93% with a 95% CI of 0.82 and 0.98. The positive and negative predictive values were 79% and 98%, respectively. This study shows that the endometrial thickness measured by vaginosonography can predict the results of the P challenge test in patients with amenorrhea.

Psychological characteristics of males with secondary erectile failure.

This study was designed to obtain objective data on the personality profiles of two groups of males with a primary complaint of erectile failure and compare them to a group of psychiatric patients unselected for sexual dysfunction and to a sexually "normal" control group. Utilizing the Eysenck Personality Inventory, the Institute of Personality and Ability Testing Anxiety Scale, Symptom Checklist, and the Minnesota Multiphasic Personality Inventory, it was determined that males applying to a university/county hospital sex-dysfunction clinic appeared similar to patients seen in the same clinic who were unselected for sex dysfunction and more psychologically disturbed than patients with the same complaint applying for treatment at a private clinic. All three groups showed more psychopathology than sexually normal males. The implications of these findings are discussed.