Renin blockade: a double-edged sword?

Aliskiren, a direct renin inhibitor, blocks the first step of the renin–angiotensin–aldosterone system (RAAS), thereby reducing plasma renin activity and the circulating levels of angiotensin I, angiotensin II, and aldosterone. Extensive RAAS blockade can be achieved through the administration of aliskiren; however, renin blockade is a double-edged sword because the renin/prorenin receptor-associated pathway is also reportedly modulated by direct renin inhibitor. This research highlight discusses the findings of a recent clinical study of aliskiren and explores the complex interactions of key molecules in the RAAS pathway in response to aliskiren administration

Structural equation model of factors related to quality of life for community-dwelling schizophrenic patients in Japan

BACKGROUND: This study aimed to clarify how community mental healthcare systems can be improved. METHODS: We included 79 schizophrenic patients, aged 20 to 80 years, residing in the Tokyo metropolitan area who regularly visited rehabilitation facilities offering assistance to psychiatric patients and were receiving treatment on an outpatient basis. No subjects had severe cognitive disorders or were taking medication with side effects that could prevent the completion of questionnaires. Questionnaires included items related to quality of life, self-efficacy, self-esteem, psychosis based on the Behavior and Symptom Identification Scale, health locus of control, and socio-demographic factors. We performed multiple linear regression analysis with quality of life as the dependent variable and, based on covariance structural analysis, evaluated the goodness of fit of the resulting structural equations models. RESULTS: Self-efficacy, self-esteem, and degree of psychosis significantly impacted quality of life. Marital status, age, and types of medications also influenced quality of life. Multiple linear regression analysis revealed psychiatric symptoms (Behavior and Symptom Identification Scale-32 [daily living and role functioning] (Beta = −0.537, p < 0.001) and self-efficacy (Beta = 0.249, p < 0.05) to be predictors of total quality of life score. Based on covariance structural analysis, the resulting model was found to exhibit reasonable goodness of fit. CONCLUSIONS: Self-efficacy had an especially strong and direct impact on QOL. Therefore, it is important to provide more positive feedback to patients, provide social skills training based on cognitive behavioral therapy, and engage patients in role playing to improve self-efficacy and self-concept

Chemical investigation of the volatile compounds of Alpinia zerumbet leaves using DH-TD-GC/MS

The aromatic perennial plant Alpinia zerumbet (Pers.) Burtt & Smith (Zingiberaceae) grows in Japan, from the southern Kyushu to the Ryukyu Islands. Recently, interspecific hybridization of Alpinia spp. was reported in Taiwan. We have demonstrated that the floral volatiles of A. zerumbet differ between individual plants [1]. We also showed that the yield, content of the major volatile compounds, enantiomeric ratio of some monoterpenes, and antioxidant activities of the A. zerumbet leaf essential oils varied significantly among individual plants [2], which reflected genetic variability within the species. However, this trend needed to be demonstrated with more individuals. Unfortunately, a large quantity of leaves is necessary to obtain sufficient essential oil to investigate the differences in the chemical composition of the oils among individuals, because A. zerumbet leaves yield only a small amount of the essential oil upon hydrodistillation (0.01–0.07%). Prompted by this, here, we combined the dynamic headspace method with thermal desorption-gas chromatography-mass spectrometry (DH-TD-GC/MS). For this method, a small piece of a leaf is used and sampling is possible directly in the field. The aims of this study were to test the effectiveness of this DH-TD-GC/MS method and reveal the variation in the chemical composition of the essential oils of the leaves among the individual plants.                A. zerumbet leaves were collected from Okinawa and Ie (16 and 22 samples, respectively), the Ryukyu Islands, between May and October 2017. The leaves were oven-dried (40–45 °C) to a moisture content of 10% or less, and 0.5 g of the dried leaves and stems from individual plants were septum-sealed in a 27-mL gas-tight vial. After introducing air through the activated carbon trap into the vial, volatiles were aspirated by a minipump and adsorbed to Tenax TA (60/80 mesh, 130 mg) for 10 min at 60 °C. Chemical analysis was performed using a TD-GC/MS system. The major volatiles identified in this study (α-pinene, camphene, limonene, β-phellandrene, 1,8-cineole, p-cymene, camphor, linalool, and cryptone) well represented the characteristics of the essential oil of the leaf. The aroma profile obtained here also confirmed that the volatiles in the leaves clearly differed among individual plants. These observations suggest the plausibility of selecting lineages of A. zerumbet to optimize the future production of valuable essential oils

Nature of collective decision-making by simple yes/no decision units Eisuke Hasegawa

The study of collective decision-making spans various fields such as brain and behavioural sciences, economics, management sciences, and artificial intelligence. Despite these interdisciplinary applications, little is known regarding how a group of simple 'yes/no' units, such as neurons in the brain, can select the best option among multiple options. One prerequisite for achieving such correct choices by the brain is correct evaluation of relative option quality, which enables a collective decision maker to efficiently choose the best option. Here, we applied a sensory discrimination mechanism using yes/no units with differential thresholds to a model for making a collective choice among multiple options. The performance corresponding to the correct choice was shown to be affected by various parameters. High performance can be achieved by tuning the threshold distribution with the options' quality distribution. The number of yes/no units allocated to each option and its variability profoundly affects performance. When this variability is large, a quorum decision becomes superior to a majority decision under some conditions. The general features of this collective decision-making by a group of simple yes/no units revealed in this study suggest that this mechanism may be useful in applications across various fields