Epithelial to Mesenchymal Transition of Mesothelial Cells in Tuberculosis Pleurisy

김좌경,이영석,황용일,엄광석,신태림,장승훈,김철홍,김동규,이명구,현인규,정기석 대한결핵 및 호흡기학회 2006 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.103 No.0

Impact of sarcopenia on long-term mortality and cardiovascular events in patients undergoing hemodialysis

김좌경,김성균,오지은,이영기,노정우,김형직,송영림 대한내과학회 2019 The Korean Journal of Internal Medicine Vol.34 No.3

Background/Aims: A high body mass index (BMI) is known to correlate with better survival in patients on hemodialysis (HD). However, the impacts of body composition and sarcopenia on survival have not been well studied in this population. Methods: One hundred and forty-two prevalent HD patients were recruited and followed prospectively for up to 4.5 years. Low muscle mass (measured using a portable, whole-body, bioimpedance spectroscopic device) was defined as a lean tissue index (LTI) two standard deviations (SD) or more below the normal gender-specific mean for young people. Low muscle strength was a handgrip strength (HGS) of less than 30 kg in males and less than 20 kg in females. Sarcopenia was considered present when both LTI and HGS were reduced. Results: The mean age was 59.8 ± 13.1 years; 57.0% were male and 47.2% had diabetes. Forty-seven patients (33.1%) had sarcopenia. During follow-up, 28 patients (19.7%) died, and low LTI (adjusted hazard ratio [HR], 2.77; 95% confidence interval [CI], 1.10 to 6.97) and low HGS (HR 5.65; 95% CI, 1.99 to 16.04) were independently associated with mortality. Sarcopenia was a significant predictor for death (HR, 6.99; 95% CI, 1.84 to 26.58; p = 0.004) and cardiovascular events (HR, 4.33; 95% CI, 1.51 to 12.43; p = 0.006). Conclusions: Sarcopenia was strongly associated with long-term mortality and cardiovascular events in HD patients. Assessment of muscle strength and muscle mass may provide additional prognostic information to survival in patients with end-stage renal disease.

전략적인 콩팥병 환자의 체수분조절 방법

김좌경 대한내과학회 2017 대한내과학회 추계학술대회 Vol.2017 No.2

Estimating Average Glucose Levels from Glycated Albumin in Patients with End-Stage Renal Disease

김좌경,유태현,박정탁,오형중,유동은,김승준,한승혁,강신욱,최규헌 연세대학교의과대학 2012 Yonsei medical journal Vol.53 No.3

Purpose: In patients with diabetic end stage renal disease (ESRD), glycated albumin (GA) reflects recent glycemic control more accurately than glycated hemoglobin (HbA1c). We evaluated the relationship between GA and average blood glucose (AG) level and developed an estimating equation for translating GA values into easier-to-understand AG levels. Materials and Methods: A total of 185 ESRD patients, including 154 diabetic and 31 non-diabetic participants, were enrolled (108 hemodialysis, 77 peritoneal dialysis). Patients were asked to perform four-point daily self-monitoring of capillary blood glucose (SMBG) at least three consecutive days each week for four weeks. Serum levels of GA, HbA1c and other biochemical parameters were checked at baseline, as well as at 4 and 8 weeks. Results:Approximately 74.3±7.0 SMBG readings were obtained from each participant and mean AG was 169.1±48.2 mg/dL. The correlation coefficient between serum GA and AG levels (r=0.70, p<0.001) was higher than that of HbA1c and AG (r=0.54, p<0.001). Linear regression analysis yielded the following equation: estimated AG (eAG) (mg/dL)=4.71×GA%+73.35, and with this formula, serum GA levels could be easily translated to eAG levels. Multivariate analysis revealed significant contributions of postprandial hyperglycemia (β=0.25, p=0.03) and serum albumin (β=0.17, p=0.04) in determining serum GA level, independent to other clinical parameters. Conclusion: Compared to HbA1c, serum GA levels were better correlated with AG levels. Using the estimating equation, an average blood glucose level of 155-160 mg/dL could be matched to a GA value of 18-19% in patients with ESRD.

Rapid Decrease of Intact Parathyroid Hormone Could Be a Predictor of Better Response to Cinacalcet in Hemodialysis Patients

김좌경,권영주,김수완,김영훈,박철휘,최규복,황승덕,최규헌 연세대학교의과대학 2013 Yonsei medical journal Vol.54 No.2

Purpose: Cinacalcet is effective for treating refractory secondary hyperparathyroidism (SHPT), but little is known about the response rates and clinical factors influencing the response. Materials and Methods: A prospective, single-arm, multi-center study was performed for 24 weeks. Cinacalcet was administered to patients with intact parathyroid hormone (iPTH) level greater than 300 pg/mL. Cinacalcet was started at a dose of 25 mg daily and titrated until 100 mg to achieve a serum iPTH level <300 pg/mL (primary end point). Early response to cinacalcet was defined as a decrease of iPTH more than 50% within one month. Results: Fifty-seven patients were examined. Based on the magnitude of iPTH decrease, patients were divided into responder (n=47, 82.5%) and non-responder (n=10, 17.5%) groups. Among the responders, 38 achieved the primary end point, whereas 9 patients showed a reduction in serum iPTH of 30% or more, but did not reach the primary end point. Compared to non-responders, responders were significantly older (p=0.026), female (p=0.041), and diabetics (p<0.001). Additionally,early response was observed more frequently in the responders (30/47, 63.8%), of whom the majority (27/30, 90.0%) achieved the primary end point. Multivariate analysis showed that lower baseline iPTH levels [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-0.99], the presence of diabetes (OR 46.45, CI 1.92-1125.6) and early response (OR 21.54, CI 2.94-157.7) were significant clinical factors affecting achievement of iPTH target. Conclusion: Cinacalcet was effective in most hemodialysis patients with refractory SHPT. The presence of an early response was closely associated with the achievement of target levels of iPTH.

노인의 급성신부전

김좌경 대한내과학회 2022 대한내과학회 추계학술대회 Vol.2022 No.2

Serum cystatin C to creatinine ratio is associated with sarcopenia in non-dialysis-dependent chronic kidney disease

안정남,김좌경,이형석,김성균,김형직,송영림 대한신장학회 2022 Kidney Research and Clinical Practice Vol.41 No.5

Background: Sarcopenia is a prevalent complication in patients with chronic kidney disease and is associated with poor quality of life, morbidity, and mortality. Several candidate biomarkers have been evaluated for this condition. This study assessed the serum cystatin C to creatinine (serum cystatin C/Cr) ratio as a potential biomarker for sarcopenia in patients with non-dialysis-dependent chronic kidney disease. Methods: This study enrolled 517 outpatients. Muscle mass (lean tissue index) was measured using a bioimpedance spectroscopic device, and muscle strength (handgrip strength) was also measured. Sarcopenia was defined as a combination of low muscle strength and low muscle mass. Results: Sarcopenia was observed in 25.5% of patients, and the mean serum cystatin C/Cr ratio was significantly higher in patients with sarcopenia than in those without it (1.14 ± 0.26 vs. 1.01 ± 0.27, p < 0.001). The prevalence of sarcopenia and low lean tissue index increased as the cystatin C/Cr ratio increased. The negative predictive value of the cystatin C/Cr ratio for sarcopenia or low lean tissue index was ≥80%. Multivariate analyses revealed that when the serum cystatin C/Cr ratio increased by 1, the risk of sarcopenia, low lean tissue index, and low handgrip strength increased by 4.6-, 7.2-, and 2.6-fold, respectively (p = 0.003, p < 0.001, and p = 0.048). The association was maximized in patients with an estimated glomerular filtration rate of <30 mL/min/1.73 m2. Conclusion: Calculating the serum cystatin C/Cr ratio could be helpful for detecting and managing sarcopenia in patients with chronic kidney disease.

다중벽 탄소나노튜브가 첨가된 나노복합재료의 열특성

김석원,김좌경,박수진,이상현 한국물리학회 2004 새물리 Vol.49 No.5

The thermal conductivity and the thermal diffusivity of chemically surface treated multi-walled carbon nanotube (MWCNT) reinforced polypropylene (PP) composites were measured using 3$\omega$ method in the temperature range of 90 - 320 K and photoacoustic (PA) spectroscopy at room temperature, respectively. Nine kinds of samples were prepared by melt-blending PP resins with 0.1, 0.5, and 2.0 wt\% additions of non-treated, nitric acid (HNO$_3$) treated, and potassium- hydroxide (KOH) treated nanotube. The samples were compression-molded at 180 $^\circ$C into about 0.5 mm thick composite films by using a hot press. The thermal conductivity was in the range from 0.05 to 0.6 W$\cdot$m$^{-1}$$\cdot$K$^{-1}$ and increased as the temperature was increased and as the CNT concentration was increased. The chemical treatment enhanced the thermal conductivities of the 0.5 and the 2.0 wt\% samples about 2 times; however, that of the 0.1 wt\% sample by didn't chang. This can be explained qualitatively by the effects of chemical treatment on reinforcing ability for CNT/polymer composites. The thermal diffusivity showed trends smilar to those for the thermal conductivity and that could be explained of by assuming that the samples had a constant density and can start specific heat. 화학적으로 표면처리된 다중벽 탄소나노튜브(MWCNT)로 강화된 폴리프로필렌(PP) 복합재료의 열전도도를 90-320 K의 온도 영역에서 3$\omega$법으로, 열확산도를 상온에서 광음향법으로 각각 측정하였다. 질산(HNO$_3$)과 수산화칼륨(KOH)으로 각각 표면처리된 탄소 나노튜브와 표면처리되지 않은 탄소나노튜브를 0.1, 0.5, 그리고 2.0 wt\%씩 용융된 PP 수지에 첨가하여 온도 190 $^\circ$C에서 두께 0.5 mm가 되게 가열압착하여 총 9종류의 시편을 만들었다. 측정된 열전도도는 0.05 W$\cdot $m$^{-1}$$\cdot$K$^{-1}$에서 0.6W$\cdot$m$^{-1}$$\cdot$K$^{-1}$ 까지 분포하며 온도상승 및 나노튜브 함량이 증가함에 증가함을 보였다. 화학적 표면처리에 따라 0.5 wt\%와 2.0 wt\%의 함량을 가진 시편은 열전도 도가 2배 가까이 증가하였으나 0.1 wt\% 함량의 시편은 거의 변하지 않았다. 이 결과들은 화학적인 표면처리에 의해서 나노튜브와 PP 수지의 밀착이 더 향상되기 때문으로 설명되어 질 수 있다. 열확산도도 나노튜브의 함량에 따라 열전도도에 비례하여 변함을 보였으며 이는 비열과 밀도가 일정하다는 가정하에서 설명이 가능하였다.

galectin-3, vascular calcification, and mortality

김나영,김좌경 대한내과학회 2023 대한내과학회 추계학술대회 Vol.2023 No.2

Prediction of death in dialysis patients using artificial intelligence

이은향,김좌경,이형석,송영림,김성균,안정남 대한내과학회 2022 대한내과학회 추계학술대회 Vol.2022 No.2