Project description:Critically ill intensive care unit (ICU) patients commonly develop severe muscle wasting and impaired muscle function, leading to delayed recovery, with subsequent increased morbidity and financial costs, and decrease quality of life of survivors. Acute Quadriplegic Myopathy (AQM) is one of the most common neuromuscular disorders associated with ICU-acquired muscle weakness. Although there are no available treatments for the ICU-acquired muscle weakness, it has been demonstrated that early mobilization can improve its prognosis and functional outcomes. This study aims at improving our understanding of the effects of passive mechanical loading on skeletal muscle structure and function by using a unique experimental rat ICU model allowing analyses of the temporal sequence of changes in mechanically ventilated and pharmacologically paralyzed animals at durations varying from 6 h to 14 days. Results show that passive mechanical loading alleviated the muscle wasting and the loss of force-generation associated with the ICU intervention, resulting in a doubling of the functional capacity of the loaded vs. unloaded muscles after a 2-week ICU intervention. We demonstrated that the improved maintenance of muscle structure and function is likely a consequence of a reduced oxidative stress, and a reduced loss of the molecular motor protein myosin. A complex temporal gene expression pattern, delineated by microarray analysis, was observed with loading-induced changes in transcript levels of sarcomeric proteins, muscle developmental processes, stress response, ECM/cell adhesion proteins and metabolism. Thus, the results from this study show that passive mechanical loading alleviates the severe negative consequences on muscle structure and function associated with mechanical silencing in ICU patients, strongly supporting early and intense physical therapy in immobilized ICU patients. This study aims to unravel the effects of passive mechanical loading on skeletal muscle structure and function in an experimental rat ICU model at duration varying between 6h and 14 days. A total of 23 experimental female Sprague-Dawley rats were included in this study. The experimental rats were anaesthetized, treated with the neuromuscular blocking agent (NMBA) M-NM-1-cobrotoxin, mechanically ventilated and monitored for durations varying from 6h to 4 days (n=13), from 5 to 8 days (n=4), and from 9 to 14 days (n=6). The left leg of the animal was activated for 6 hours at the shortest duration and 12 hours per day at durations 12 hours and longer throughout the experiment, using a mechanical lever arm that produced a continuous passive maximal ankle joint flexions-extensions at a speed of 13.3 cycles per minute. Muscle biopsies were obtained from gastrocnemius muscle (proximal part) immediately after euthanasia, were quickly frozen in liquid propane cooled by liquid nitrogen, and stored at -80M-BM-0C. RNA was extracted.
Project description:Critically ill intensive care unit (ICU) patients commonly develop severe muscle wasting and impaired muscle function, leading to delayed recovery, with subsequent increased morbidity and financial costs, and decrease quality of life of survivors. Acute Quadriplegic Myopathy (AQM) is one of the most common neuromuscular disorders associated with ICU-acquired muscle weakness. Although there are no available treatments for the ICU-acquired muscle weakness, it has been demonstrated that early mobilization can improve its prognosis and functional outcomes. This study aims at improving our understanding of the effects of passive mechanical loading on skeletal muscle structure and function by using a unique experimental rat ICU model allowing analyses of the temporal sequence of changes in mechanically ventilated and pharmacologically paralyzed animals at durations varying from 6 h to 14 days. Results show that passive mechanical loading alleviated the muscle wasting and the loss of force-generation associated with the ICU intervention, resulting in a doubling of the functional capacity of the loaded vs. unloaded muscles after a 2-week ICU intervention. We demonstrated that the improved maintenance of muscle structure and function is likely a consequence of a reduced oxidative stress, and a reduced loss of the molecular motor protein myosin. A complex temporal gene expression pattern, delineated by microarray analysis, was observed with loading-induced changes in transcript levels of sarcomeric proteins, muscle developmental processes, stress response, ECM/cell adhesion proteins and metabolism. Thus, the results from this study show that passive mechanical loading alleviates the severe negative consequences on muscle structure and function associated with mechanical silencing in ICU patients, strongly supporting early and intense physical therapy in immobilized ICU patients.
Project description:In the last decade, Candida krusei has caused multiple outbreaks of candidemia in Neonatal Intensive Care Units (NICUs) in low-and middle-income countries such as Brazil, India, and South Africa. In India, C. krusei ranks as the sixth cause of candidemia in adult ICUs. Additionally, sporadic outbreaks of nosocomial candidemia in the NICUs are widely reported from India. However, the genetic population of C. krusei causing outbreaks remain largely unknown. In the present study, we used whole genome sequencing to examine the genetic structure of C. krusei population causing candidemia spanning a period of five years (2015-20) in a single NICU in Delhi, India. Further, to evaluate the mechanisms of azole antifungal resistance in C. krusei, we compare the transcriptomic profiles of fluconazole susceptible (FLU-S) and resistant (FLU-R) isolates. Transcriptomic assay was performed in logarithmically growing C. krusei clinical isolates 123/P/19 and 1390/P/18 strains. STAR aligner v.2.5.2b was used to sequence the trimmed reads with the specified reference genome of P. kudriavzevii to determine the unique gene hit counts. A total of 178 genes were differentially expressed by at least 1.5-fold in 1390/P/18 as compared to 123/P/19 isolate. Principal component analysis (PCA) of normalized read counts also depicted almost similar transcriptomic profile between the two C. krusei strains with 53 % variance at principal component 1. Out of 178 differentially expressed genes, 72 were up-regulated and 106 were down-regulated in 1390/P/18 strain compared to 123/P/19 strain. Functionally, genes associated with transport (n=10), mitogen activated protein kinase signaling (MAPK; n=8), transcription factors (TF; n=6) and ergosterol biosynthesis (n=3) were expressed differentially.