An attempt was made to reestablish the virus-like agent associated with rat pneumonia by the nasal instillation of the infectious material into supposedly normal young rats from the selected Princeton colony. The incidence of the pneumonia in these animals after the injection of suspensions of pneumonic lungs from either rats or mice was not significantly greater than the incidence under natural conditions. In attempting to account for the refractory state of the immature rats it was found that the agent was widely dispersed through the breeding colony at an early age. Detailed tests of many litters indicated that the agent was acquired shortly after birth by way of the upper air passages as the result of maternal contact. In most instances it was so well tolerated by young rats during the suckling period and for several months thereafter that its presence was recognized only by nasal transfer to mice. There is every indication that the rate of infection of rats in the breeding colony approaches 100 per cent by the time the animals are old enough to be used experimentally.
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http://dx.doi.org/10.1084/jem.87.1.11 | DOI Listing |
Although the toxic effect of Sedentary behavior (SED) on bone health has been demonstrated in the previous study, the underlying mechanisms of SED, or break SED to bone health remain unclear. In this study, we aim to investigate the effects of sedentary behavior (SED) on bone health, as well as the potential favor effects of moderate to vigorous physical activity (MVPA) and periodic interruptions of SED. To simulate SED, we used small Plexiglas cages (20.
View Article and Find Full Text PDFbioRxiv
December 2024
Neuroscience Institute, Georgia State University, 100 Piedmont Ave., Atlanta, GA, 30303.
It is currently estimated that every 15 minutes an infant is born with opioid use disorder and undergoes intense early life trauma due to opioid withdrawal. Clinical research on the long-term consequences of gestational opioid exposure reports increased rates of social, conduct, and emotional disorders in these children. Here, we investigate the impact of perinatal opioid exposure (POE) on behaviors associated with anhedonia and stress in male and female Sprague Dawley rats.
View Article and Find Full Text PDFBMC Genomics
January 2025
Integrative Genomics of Ageing Group, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK.
Age-related muscle wasting, sarcopenia is an extensive loss of muscle mass and strength with age and a major cause of disability and accidents in the elderly. Mechanisms purported to be involved in muscle ageing and sarcopenia are numerous but poorly understood, necessitating deeper study. Hence, we employed high-throughput RNA sequencing to survey the global changes in protein-coding gene expression occurring in skeletal muscle with age.
View Article and Find Full Text PDFNeurosci Lett
January 2025
Neurophysiology Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Urmia, Iran. Electronic address:
Brain aging is the leading risk factor for most neurodegenerative diseases and has been linked with high rates of neuron loss. Thus, identifying molecular mechanisms underlying neuron loss and pharmacological modulation may be of great importance for slowing or preventing age-related diseases. Herein, we investigated the roles of miR-92a, Akt, mTOR, and NF-κB in age-associated apoptosis in the hippocampus (a critical structure involved in brain aging) of male rats alone and in combination with prazosin.
View Article and Find Full Text PDFCell Mol Biol (Noisy-le-grand)
January 2025
Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
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