Biology subjects

Curran, D.

Publications and source records attributed to Curran, D..

3 recordsLinked to original sources

bioRxiv2026

Whos been sleeping in my bedroom? Sleep and cardiorespiratory physiology when co-sleeping with a dog, cat, or child

Co-sleeping with pets or children is common, yet its effects on sleep, cardiorespiratory physiology, and behavioral outcomes are understudied. We examined within-person associations between co-sleeping with a dog, cat, or child and sleep characteristics, measures of cardiorespiratory physiology, and next-day physical activity in 1,649,083 person-days from 11,733 adults wearing the WHOOP wearable device. Participants reported nightly co-sleeping via a daily journal in the devices companion smartphone application, and linear mixed-effects models compared nights with and without co-sleeping within the same individual. Co-sleeping was associated with modest improvements in cardiorespiratory physiology, including lower resting heart rate (0.8-1.1 beats/min), lower respiratory rate (0.04-0.07 breaths/min), and higher heart rate variability (1.41-1.95 ms). Sleep outcomes were mixed, with longer sleep duration (5.5-9.6 min) but more disturbances (0.36-0.40 instances) and slightly less restorative sleep (0.23-1.17%). Associations were generally consistent across groups, although child co-sleeping showed greater sleep disruption. Next-day physical activity was higher following dog and cat co-sleeping (7.6 and 7.4 intensity-weighted min, respectively) but lower following child co-sleeping (2.6 intensity-weighted min). Although effect sizes were small ({beta} range: 0.008-0.045), findings suggest that co-sleeping is associated with a trade-off between modest cardiorespiratory benefits and mild sleep disruption, indicating that co-sleeping decisions may be driven more by personal and contextual factors than by concerns about physiologic impact.

physiology↗

bioRxiv2020

Actinobacillus utilizes a binding-protein dependent ABC transporter to acquire Vitamin B6

Bacteria require high efficiency uptake systems to survive and proliferate in nutrient limiting environments, such as those found in the host. The ABC transporters at the bacterial plasma membrane provide a mechanism for transport of many substrates. We recently demonstrated that an AfuABC operon, previously annotated as encoding a ferrous iron uptake system, is in fact a cyclic hexose/heptose-phosphate transporter with high selectivity and specificity for these metabolites. In this study, we examine a second operon containing a periplasmic binding protein discovered in Actinobacillus for its potential role in nutrient acquisition. Using electron density obtained from the crystal structure of the periplasmic binding protein we modeled a pyridoxal-5-phosphate (P5P/PLP/Vitamin B6) ligand into the atomic resolution electron density map. The identity of the Vitamin B6 bound to this periplasmic binding protein was verified by isothermal titration calorimetry, microscale thermophoresis, and mass spectrometry, leading us to name the protein P5PA and the operon P5PAB. To illustrate the functional utility of this uptake system, we introduced the P5PAB operon from A. pleuropneumoniae into an E. coli K-12 strain that was devoid of a key enzyme required for Vitamin B6 synthesis. The growth of this strain at low levels of Vitamin B6 supports the role of this newly identify operon in Vitamin B6 uptake.

biochemistry↗

bioRxiv2019

Lymph node follicle formation and vaccination responses reconstituted in vitro in a human Organ Chip

Lymphoid follicles (LFs) are responsible for generation of adaptive immune responses in secondary lymphoid organs and form ectopically during chronic inflammation. A human model of LF formation would provide a tool to understand LF development and an alternative to non-human primate models for preclinical evaluation of vaccines. Here, we show that primary human blood B- and T-lymphocytes autonomously assemble into ectopic LFs when cultured in a three-dimensional (3D) extracellular matrix gel within an organ-on-a-chip microfluidic device. Dynamic fluid flow is required for LF formation and prevention of lymphocyte autoactivation. These germinal center-like LFs contain B cells expressing Activation-Induced Cytidine Deaminase and exhibit plasma cell (PC) differentiation upon activation. To explore their utility for vaccine testing, autologous monocyte-derived dendritic cells were integrated into LF Chips. The human LF chips demonstrated improved antibody responses to split virion influenza vaccination compared to 2D cultures, which were enhanced by addition of a squalene-in-water emulsion adjuvant, and this was accompanied by increases in LF size and number. When inoculated with commercial influenza vaccine, PC formation and production of anti-hemagglutinin IgG were observed, as well as secretion of cytokines similar to those observed in vaccinated humans over clinically relevant timescales.

immunology↗