Aims: To test the hypothesis that apnoea of infancy (AOI) is due to a deficit in chemoreception.
Methods: Tests were performed on 112 infants: 43 healthy control infants, 28 infants with periodic breathing or central apnoea (PBCA), and 41 infants with obstructive apnoea (OA) on overnight polysomnography. Chemoreceptor responses to hypercapnia (4% and 6% CO2 in air) for 6-8 minutes and hyperoxia (100% O2) for 60 seconds were expressed in terms of response strength and reaction time. Age at birth (gestational week 37-41) and age at test (2-34 postnatal weeks) were comparable across groups (median, min-max value). A total of 70 CO2 and 71 O2 tests were analysed.
Results: The strongest and fastest CO2 responders were control infants: their median increase in ventilation was 291%/kPaCO2 and their reaction time 16 breaths. In infants with PBCA and OA, the increase in ventilation was 41% and 130%/kPaCO2, and reaction time 64 and 54 breaths, respectively. There was a significant negative correlation between CO2 response strength and response time. In response to hyperoxia there was a comparable decrease in ventilation in all infants (12-20%), but a significantly longer response time in infants with apnoea (20 v 12 breaths). There was no correlation between the response strength and response time to O2 and CO2.
Conclusion: An inappropriate central control of respiration is an important mechanism in the pathogenesis of apnoea of infancy.
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http://dx.doi.org/10.1136/adc.2003.030957 | DOI Listing |
Birth Defects Res
January 2025
School of Nursing, Ulster University Belfast, Belfast, Northern Ireland, UK.
Introduction: While improved medical and surgical care for children with pina bifida has improved their survival, some may have lower cognitive, behavioral and educational performance. The paper assesses the effect of spina bifida on cognitive, behavioral, and educational outcomes in 5-11 year olds.
Methods: A cross-sectional study design was used where data were collected from parents/guardians and teachers using Behavior Rating Inventory of Executive Function, second edition (BRIEF2), Strengths and Difficulties Questionnaire (SDQ), and Teacher Academic Attainment Scale (TAAS).
Biophys J
January 2025
Department of Pharmacology, University of California Davis, California 95616.
In every heartbeat, cardiac muscle cells perform excitation-Ca signaling-contraction (EC) coupling to pump blood against the vascular resistance. Cardiomyocytes can sense the mechanical load and activate mechano-chemo-transduction (MCT) mechanism, which provides feedback regulation of EC coupling. MCT feedback is important for the heart to upregulate contraction in response to increased load to maintain cardiac output.
View Article and Find Full Text PDFSci Rep
January 2025
School of Resource, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
In natural environments, most rocks possess internal fissures and are often exposed to diverse external loads arising from engineering activities and ground stress, among other factors. This study aims to explore the influence of different loading rates on the mechanical properties and acoustic emission (AE) characteristics of fissured rocks and to develop an intrinsic damage model. To achieve this, prefabricated fissured rock specimens that mimic natural rocks were prepared.
View Article and Find Full Text PDFSci Rep
January 2025
School of Gerontology and Long-Term Care, Taipei Medical University, Taipei City 110, Taiwan (R.O.C.), Taipei, Taiwan.
To examine the dose-response relationship between specific types of exercise for improving walking velocity in Parkinson's disease (PD). This systematic review and network meta-analysis included searches of PubMed, Medline, Embase, PsycINFO, Cochrane Library, and Web of Science were searched from inception until February 18th, 2024. Data analysis was performed using R software with the MBNMA and RJAGS packages.
View Article and Find Full Text PDFNat Commun
January 2025
Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
Mediator25 (MED25) has been ascribed as a signal-processing and -integrating center that controls jasmonate (JA)-induced and MYC2-dependent transcriptional output. A better understanding of the regulation of MED25 stability will undoubtedly advance our knowledge of the precise regulation of JA signaling-related transcriptional output. Here, we report that Arabidopsis MED16 activates JA-responsive gene expression by promoting MED25 stability.
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