Journal of Korean medical science
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J. Korean Med. Sci. · Sep 2014
Bilirubin activates transcription of HIF-1α in human proximal tubular cells cultured in the physiologic oxygen content.
The expression of hypoxia-inducible factor (HIF) is influenced by reactive oxygen species (ROS). Effect of bilirubin on HIF-1 expression in proximal tubular cells was investigated under physiological oxygen concentration, which is relative hypoxic condition mimicking oxygen content in the medulla of renal tissue. The human kidney (HK2) cells were cultured in 5% oxygen with or without bilirubin. ⋯ Exogenous H2O2 decreased the phosphorylation of P70S6 kinase, which was completely reversed by bilirubin treatment. Knockdown of NOX4 gene by small interfering RNA (siRNA) increased HIF-1α mRNA expression. In coonclusion, bilirubin enhances HIF-1α transcription as well as the up-regulation of HIF-1α protein translation through the attenuation of ROS and subunits of NADPH oxidase.
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J. Korean Med. Sci. · Sep 2014
Estimating 24-hour urine sodium level with spot urine sodium and creatinine.
The 24-hr urine sodium excretion level was estimated based on the spot urine sodium, and the efficacy of the formula was validated to determine the status of low salt intake <100 mEq Na/day. The 24-hr urine samples were collected from 400 patients. The 24-hr urine creatinine level was estimated with the use of three formulas: a newly derived Korean equation (E24UCR_K), and Tanaka (E24UCR_T) and Cockcroft-Gault (E24UCR_CG) equations. ⋯ After estimating the 24-hr urine sodium levels, the correlation coefficients between the estimated and measured 24-hr urine sodium levels were 0.466, 0.490, and 0.516, respectively (All P<0.001). The sensitivity of three formulas to estimate the measured 24-hr urine sodium≥100 mEq/day using the estimated amount≥100 mEq/day was 84.3%, 87.6%, and 84.8%, respectively. In conclusion, the three equations used to estimate the 24-hr urine sodium content were useful to determine the status of low salt intake.
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J. Korean Med. Sci. · Sep 2014
Estimation of daily salt intake through a 24-hour urine collection in Pohang, Korea.
There is an established relationship between a high salt diet and public health problems, especially hypertension and cardiovascular disease. We estimated daily salt intake in a group of adults and assessed its association with related variables in Pohang, Korea. We conducted a cross-sectional survey in 2013 with 242 adults. ⋯ A preference for Korean soup or stew was associated with high salt intake (P=0.038). Dietary salt intake in Korean adults is still higher than the recommendation from the World Health Organization. More efforts should be made to reduce the salt consumption of Korean adults.
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J. Korean Med. Sci. · Sep 2014
Neural changes associated with emotion processing in children experiencing peer rejection: a functional MRI study.
This study was performed to investigate differences between children who did and did not experience peer rejection in psychological state through surveys and in emotion processing during an interpersonal stress challenge task to reflect naturalistic interpersonal face-to-face relationships. A total of 20 right-handed children, 10 to 12 yr of age, completed self-rating questionnaires inquiring about peer rejection in school, depression, and anxiety. They then underwent an interpersonal stress challenge task simulating conditions of emotional stress, in reaction to positive, negative and neutral facial expression stimuli, using interpersonal feedbacks, and functional magnetic resonance imaging (FMRI) for an analysis of neural correlates during the task. ⋯ Based on the behavioral results, the peer-rejection group exhibited elevated levels of depression, state anxiety, trait anxiety and social anxiety as compared to the control group. The FMRI results revealed that the peer-rejection group exhibited greater and remarkably more extensive activation of brain regions encompassing the amygdala, orbitofrontal cortex and ventrolateral prefrontal cortex in response to negative feedback stimuli of emotional faces. The different brain reactivities characterizing emotion processing during interpersonal relationships may be present between children who do and do not experience peer rejection.
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J. Korean Med. Sci. · Sep 2014
Urinary sodium excretion has positive correlation with activation of urinary renin angiotensin system and reactive oxygen species in hypertensive chronic kidney disease.
It is not well described the pathophysiology of renal injuries caused by a high salt intake in humans. The authors analyzed the relationship between the 24-hr urine sodium-to-creatinine ratio (24HUna/cr) and renal injury parameters such as urine angiotensinogen (uAGT/cr), monocyte chemoattractant peptide-1 (uMCP1/cr), and malondialdehyde-to-creatinine ratio (uMDA/cr) by using the data derived from 226 hypertensive chronic kidney disease patients. At baseline, the 24HUna/cr group or levels had a positive correlation with uAGT/cr and uMDA/cr adjusted for related factors (P<0.001 for each analysis). ⋯ Similarly, uMDA/cr was estimated as 0.17 (95% CI, 0.14-0.21) pM/mg cr in patients with <100 mEq/g cr and 0.27 (95% CI, 0.20-0.33) pM/mg cr in patients with ≥200 mEq/g cr (P=0.016). During the 16-week follow-up period, an increase in urinary sodium excretion predicted an increase in urinary angiotensinogen excretion. In conclusion, high salt intake increases renal renin-angiotensin-system (RAS) activation, primarily, and directly or indirectly affects the production of reactive oxygen species through renal RAS activation.