Browsing by Author "Ma, Ning"

Now showing 1 - 3 of 3
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    Lipocalin 2: could it be a new biomarker in pediatric pulmonary hypertension associated with congenital heart disease?
    (IMR Press, 2021) Zhang, Hongju; Sun, Tao; Yang, Jiao; Sun, Yan; Liu, Guowen; Krittanawong, Chayakrit; El-Am, Edward A.; Bou Chaaya, Rody G.; Xu, Liyuan; Ye, Zankai; Li, Zhiqiang; Ma, Ning; Medicine, School of Medicine
    The role of lipocalin 2 (LCN2) in pulmonary hypertension (PH) in pediatric patients with congenital heart disease (CHD) remains unclear. We sought to investigate whether LCN2 could be a potential biomarker for PH in pediatric patients who underwent surgery for CHD. From December 2018 to February 2020, patients undergoing surgical repair for congenital defects with and without PH were identified. Healthy children without CHD and PH served as controls. A mean pulmonary artery pressure (mPAP) >20 mmHg was used as the definition of PH. Blood samples and echocardiograms were obtained in all patients and right heart catheterization was performed in 79 patients. Multivariable logistic regression analysis was used to determine potential predictors for PH. Among 102 patients, the median age was 10 [Interquartile range (IQR) 7.0-13] months, and 37.5% were female. Compared to non-PH patients and controls, PH patients showed elevated levels of LCN2 (P < 0.001). In addition, LCN2 levels positively correlated with the invasive haemodynamic indices of PH. In univariate regression, LCN2 (odds ratio = 2.69 [1.06-5.31], P < 0.001), N-Terminal pro Brain Natriuretic Peptide (NT-proBNP) (OR = 1.91 [1.21-7.56], P = 0.03) and high-sensitive troponin T (hsTnT) (OR = 1.36 [1.01-3.57], P = 0.01) were associated with PH; however, only LCN2 (OR = 1.68 [1.04-4.52], P = 0.03) was significantly associated with PH on multivariate analysis. In conclusion, children with PH had increased LCN2 expression. LCN2 levels positively correlated with invasive indices of PH. These results indicate LCN2 could be a useful biomarker for prediction of PH in pediatric CHD cases.
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    Quantifying the Controls on Evapotranspiration Partitioning in the Highest Alpine Meadow Ecosystem
    (AGU, 2020-04) Cui, Jiangpeng; Tian, Lide; Wei, Zhongwang; Huntingford, Chris; Wang, Pei; Cui, Zhongyin; Ma, Ning; Wang, Lixin; Earth Sciences, School of Science
    Quantifying the transpiration fraction of evapotranspiration (T/ET) is crucial for understanding plant functionality in ecosystem water cycles, land‐atmosphere interactions, and the global water budget. However, the controls and mechanisms underlying the temporal change of T/ET remain poorly understood in arid and semiarid areas, especially for remote regions with sparse observations such as the Tibetan Plateau (TP). In this study, we used combined high‐frequency laser spectroscopy and chamber methods to constrain estimates of T/ET for an alpine meadow ecosystem in the central TP. The three isotopic end members in ET (δET), soil evaporation (δE), and plant transpiration (δT) were directly determined by three newly customized chambers. Results showed that the seasonal variations of δET, δE, and δT were strongly affected by the precipitation isotope (R2 = 0.53). The δ18O‐based T/ET agreed with that of δ2H. Isotope‐based T/ET ranged from 0.15 to 0.73 during the periods of observation, with an average of 0.43. This mean result was supported by T/ET derived from a two‐source model and eddy covariance observations. Our overarching finding is that at the seasonal timescale, surface soil water content (θ) dominated the change of T/ET, with leaf area index playing only a secondary role. Our study confirms the critical impact of soil water on the temporal change of T/ET in water‐limited regions such as the TP. This knowledge sheds light on diverse land‐surface processes, global hydrological cycles, and their modeling.
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    Single-Limb Irradiation Induces Local and Systemic Bone Loss in a Murine Model
    (Wiley Blackwell (John Wiley & Sons), 2015-07) Wright, Laura E.; Buijs, Jeroen T.; Kim, Hun-Soo; Coats, Laura E.; Scheidler, Anne M.; John, Sutha K.; She, Yun; Murthy, Sreemala; Ma, Ning; Chin-Sinex, Helen J.; Bellido, Teresita M.; Bateman, Ted A.; Mendonca, Marc S.; Mohammad, Khalid S.; Guise, Theresa A.; Department of Medicine, IU School of Medicine
    Increased fracture risk is commonly reported in cancer patients receiving radiotherapy, particularly at sites within the field of treatment. The direct and systemic effects of ionizing radiation on bone at a therapeutic dose are not well-characterized in clinically relevant animal models. Using 20-week-old male C57Bl/6 mice, effects of irradiation (right hindlimb; 2 Gy) on bone volume and microarchitecture were evaluated prospectively by microcomputed tomography and histomorphometry and compared to contralateral-shielded bone (left hindlimb) and non-irradiated control bone. One week postirradiation, trabecular bone volume declined in irradiated tibias (-22%; p < 0.0001) and femurs (-14%; p = 0.0586) and microarchitectural parameters were compromised. Trabecular bone volume declined in contralateral tibias (-17%; p = 0.003), and no loss was detected at the femur. Osteoclast number, apoptotic osteocyte number, and marrow adiposity were increased in irradiated bone relative to contralateral and non-irradiated bone, whereas osteoblast number was unchanged. Despite no change in osteoblast number 1 week postirradiation, dynamic bone formation indices revealed a reduction in mineralized bone surface and a concomitant increase in unmineralized osteoid surface area in irradiated bone relative to contralateral and non-irradiated control bone. Further, dose-dependent and time-dependent calvarial culture and in vitro assays confirmed that calvarial osteoblasts and osteoblast-like MC3T3 cells were relatively radioresistant, whereas calvarial osteocyte and osteocyte-like MLO-Y4 cell apoptosis was induced as early as 48 hours postirradiation (4 Gy). In osteoclastogenesis assays, radiation exposure (8 Gy) stimulated murine macrophage RAW264.7 cell differentiation, and coculture of irradiated RAW264.7 cells with MLO-Y4 or murine bone marrow cells enhanced this effect. These studies highlight the multifaceted nature of radiation-induced bone loss by demonstrating direct and systemic effects on bone and its many cell types using clinically relevant doses; they have important implications for bone health in patients treated with radiation therapy.