Biology subjects

Choi, Y. B.

Publications and source records attributed to Choi, Y. B..

3 recordsLinked to original sources

bioRxiv2019

Sarcopenia is an independent predictor of hospitalization in chronic kidney disease outpatients

BackgroundPatients with chronic kidney disease (CKD) experience much more marked and earlier muscle wasting than subjects who do not have chronic illnesses. However, a few studies that have examined sarcopenia have been reported in CKD patients. We investigated the prevalence of sarcopenia in predialysis and dialysis outpatients with CKD and explored its relationship with the clinical outcomes.\n\nMeasurementsSarcopenia was defined as reduced muscle strength accompanied by decreased adjusted appendicular skeletal muscle (ASM), while those patients who exhibited only one of these characteristics were categorized as presarcopenic patients. ASM was measured by bioimpedence analysis, and muscle strength was evaluated by handgrips. ASM was adjusted by weight (ASM/wt). Patients were prospectively followed for up to 2 years.\n\nResultsOne hundred seventy-nine patients were recruited (114 male and 65 female patients who were classified into 103 predialysis patients and 76 dialysis patients, with 44.7% having diabetes). Their mean age was 60.6 {+/-} 13.5 years old. The prevalence of sarcopenia was 9.5%, while 55.9% of the patients were categorized as presarcopenic. The ASM/wt index showed significant correlations with age, handgrip strength, HOMA-IR and frailty scores. Multivariate Cox proportional hazards models demonstrated that the risk of hospitalization was significantly higher for patients with presarcopenia [hazard ratio (HR), 2.48; 95% confidence interval (CI), 1.180-5.230], and the risk of hospitalization was much higher for patients with sarcopenia than for patients in the nonsarcopenic group (HR, 9.11; 95% CI, 2.295-25.182)\n\nConclusionsSarcopenia and presarcopenia, which were defined using the ASM/wt index and handgrip strength, predicted a poorer, hospitalization-free survival in CKD patients

scientific communication and education↗

bioRxiv2018

Activation of NIX-mediated mitophagy and replication by an interferon regulatory factor homologue of human herpesvirus

Viral control of mitochondrial quality and content has emerged as an important mechanism for counteracting the host response to virus infection. Despite the knowledge of this crucial function of some viruses, little is known about how herpesviruses regulate mitochondrial homeostasis during infection. Human herpesvirus 8 (HHV-8) is an oncogenic virus causally related to AIDS-associated malignancies. Here, we found that HHV-8-encoded viral interferon regulatory factor 1 (vIRF-1) promotes mitochondrial clearance by activating mitophagy to support virus replication. Genetic interference with vIRF-1 expression or targeting to the mitochondria inhibits HHV-8 replication-induced mitophagy and leads to an accumulation of mitochondria. Moreover, vIRF-1 binds directly to a mitophagy receptor, NIX, on the mitochondria and activates NIX-mediated mitophagy to promote mitochondrial clearance. Genetic and pharmacological interruption of vIRF-1/NIX-activated mitophagy inhibits HHV-8 productive replication. In short, our findings uncover an essential role of vIRF-1 in mitophagy activation for successful lytic replication of HHV-8.

microbiology↗

bioRxiv2018

Neural Dynamics of Executive Function in Cognitively-able Kindergarteners with Autism Spectrum Disorders (ASD) as Predictors of Concurrent Academic Achievement: Preliminary Study

Although electrophysiological (EEG) measures of executive functions (EF) (e.g. error monitoring) have been used to predict academic achievement in typically developing (TD) children, work investigating a link between error monitoring, and academic skills in children with autism spectrum disorder (ASD) is limited. In the current study, we employed traditional electrophysiological and advanced time-frequency methods, combined with principal components analyses, to extract neural activity related to error monitoring, and tested their relations to academic achievement in cognitively-able kindergarteners with ASD. Thirty-five cognitively-able kindergarteners with ASD completed academic assessments and the child-friendly \"Zoo Game\" Go/No-go task at school entry. The Go/No-go task successfully elicited an error-related negativity (ERN) and error positivity (Pe) in children with ASD as young as 5 years at medio-frontal and posterior electrode sites, respectively. We also observed increased response-related theta power during errors relative to correct trials at medio-frontal sites. Both larger Pe and theta power significantly predicted concurrent academic achievement after controlling for behavioral performance on the Zoo Game and IQ. These results suggest that the use of time frequency EEG analyses, combined with traditional ERP measures, may provide new opportunities to investigate neurobiological mechanisms of EF and academic achievement in young children with ASD.

neuroscience↗