Causal dynamics of sleep, circadian rhythm, and mood symptoms in patients with major depression and bipolar disorder: insights from longitudinal wearable device data.

BACKGROUND: Sleep and circadian rhythm disruptions are common in patients with mood disorders. The intricate relationship between these disruptions and mood has been investigated, but their causal dynamics remain unknown. METHODS: We analysed data from 139 patients (76 female, mean age = 23.5 ± 3.64 years) with mood disorders who participated in a prospective observational study in South Korea. The patients wore wearable devices to monitor sleep and engaged in smartphone-delivered ecological momentary assessment of mood symptoms. Using a mathematical model, we estimated their daily circadian phase based on sleep data. Subsequently, we obtained daily time series for sleep/circadian phase estimates and mood symptoms spanning >40,000 days. We analysed the causal relationship between the time series using transfer entropy, a non-linear causal inference method. FINDINGS: The transfer entropy analysis suggested causality from circadian phase disturbance to mood symptoms in both patients with MDD (n = 45) and BD type I (n = 35), as 66.7% and 85.7% of the patients with a large dataset (>600 days) showed causality, but not in patients with BD type II (n = 59). Surprisingly, no causal relationship was suggested between sleep phase disturbances and mood symptoms. INTERPRETATION: Our findings suggest that in patients with mood disorders, circadian phase disturbances directly precede mood symptoms. This underscores the potential of targeting circadian rhythms in digital medicine, such as sleep or light exposure interventions, to restore circadian phase and thereby manage mood disorders effectively. FUNDING: Institute for Basic Science, the Human Frontiers Science Program Organization, the National Research Foundation of Korea, and the Ministry of Health & Welfare of South Korea.

Aislamiento de Streptomyces ssp: productores de antibióticos de suelos de Magallanes, XII Región de Chile / Isolation of Streptomyces: producing antibiotics from soils of Magallanes, XII Region of Chile

Muchas cepas de Actinomycetes sintetizan compuestos biodinámicos que se aprovechan como antimicrobianos o sustancias líticas o degradativas de moléculas resistentes, por lo cual se los ha pesquisado en los suelos más diversos del mundo y sobre todo en zonas aún no perturbadas por la acción del humano. Los suelos chilenos y en especial los de la XII (Magallanes) presentan características únicas, por factores climaticos y de aislamiento y tienen una diversidad característica. En esta investigación se estudiaron muestras de suelos de siete estaciones continentales de la XII Región. De 65 muestras de suelos obtenidas, 73.8 por ciento resultaron positivas, aislándose 86 cepas de Streptomyces. Se ensayó la actividad antibiótica mediante la técnica de discos KÅster y Williams y se encontró que el 59.3 por ciento presentaron actividad para algunas de las cepas de referencia, observándose una mayor frecuencia inhibitoria sobre Staphylococcus areus y Bacillus subtilis simultáneamente. Se realizó la extracción de los productos activos mediante solventes de distinta polaridad. Los extractos de n-hexano y cloroformo resultaron ser los más activos.