体重指数与早期移植肾功能的关系

目的  探讨体重指数(BMI)与早期移植肾功能的关系。方法  回顾性研究2003年11月至2014年11月在新疆医科大学第一附属医院肾病科接受同种异体活体肾移植的133例受者的临床资料。根据移植前的BMI将受者分为3组, 消瘦组(BMI < 18.5 kg/m²)、正常体重组(BMI 18.5~23.9 kg/m²)、超重肥胖组(BMI>23.9 kg/m²)。比较3组受者术后1周的实验室指标[血尿素氮(BUN)、血清肌酐(Scr)、血红蛋白、血清白蛋白、总胆固醇和甘油三酯]、移植肾功能延迟恢复发生率, 并对肾移植受者Scr与BMI进行相关分析。结果  3组受者的Scr水平比较差异有统计学意义(P < 0.05);两两比较, 超重肥胖组Scr水平高于正常体重组, 差异有统计学意义(Z=-3.408, P=0.01)。3组肾移植受者血红蛋白、血清白蛋白、总胆固醇水平差异均无统计学意义(均为P>0.05)。肾移植受者Scr水平与BMI呈正相关(r=0.187, P=0.031), Scr水平随BMI增加而升高。结论  BMI影响早期移植肾功能恢复, 肾移植术前控制体重, 有助于改善移植肾功能。     

氢分子及其制品对肺移植保护作用的研究进展

肺移植术后缺血-再灌注损伤是导致原发性移植物功能障碍的主要原因,进而会降低肺移植受者的移植肺功能和总体生存率。氢分子作为一种生理调节性分子,具有抗炎、改善氧化应激、减轻直接细胞损伤和缓解上皮细胞水肿等作用。近年来,越来越多的研究证明氢分子及其制品（主要是氢气和富氢溶液）可以显著改善肺移植术后缺血-再灌注损伤等并发症。本文就氢分子及其制品在肺移植中的保护作用及具体机制进行回顾总结,旨在为氢分子及其制品作为一种新的肺移植相关并发症治疗手段提供理论依据,进而改善肺移植受者的总体预后及生活质量。     

Emerging and Legacy Perfluoroalkyl Substances in Breastfed Chinese Infants: Renal Clearance,Body Burden,and Implications

Background: Human breast milk is a primary route of exposure to perfluoroalkyl substances (PFAS) in infants. To understand the associated risks, the occurrence of PFAS in human milk and the toxicokinetics of PFAS in infants need to be addressed.Objectives: We determined levels of emerging and legacy PFAS in human milk and urine samples from Chinese breastfed infants, estimated renal clearance, and predicted infant serum PFAS levels.Methods: In total, human milk samples were collected from 1,151 lactating mothers in 21 cities in China. In addition, 80 paired infant cord blood and urine samples were obtained from two cities. Nine emerging PFAS and 13 legacy PFAS were analyzed in the samples using ultra high-performance liquid chromatography tandem mass spectrometry. Renal clearance rates (CLrenals) of PFAS were estimated in the paired samples. PFAS serum concentrations in infants (<1 year of age) were predicted using a first-order pharmacokinetic model.Results: All nine emerging PFAS were detected in human milk, with the detection rates of 6:2 Cl-PFESA, PFMOAA, and PFO5DoDA all exceeding 70%. The level of 6:2 Cl-PFESA in human milk (median concentration=13.6 ng/L) ranked third after PFOA (336 ng/L) and PFOS (49.7 ng/L). The estimated daily intake (EDI) values of PFOA and PFOS exceeded the reference dose (RfD) of 20 ng/kg BW per day recommended by the U.S. Environmental Protection Agency in 78% and 17% of breastfed infant samples, respectively. 6:2 Cl-PFESA had the lowest infant CLrenal (0.009mL/kg BW per day), corresponding to the longest estimated half-life of 49 y. The average half-lives of PFMOAA, PFO2HxA, and PFO3OA were 0.221, 0.075, and 0.304 y, respectively. The CLrenals of PFOA, PFNA, and PFDA were slower in infants than in adults.Conclusions: Our results demonstrate the widespread occurrence of emerging PFAS in human milk in China. The relatively high EDIs and half-lives of emerging PFAS suggest potential health risks of postnatal exposure in newborns. https://doi.org/10.1289/{"type":"entrez-protein","attrs":{"text":"EHP11403","term_id":"372010800","term_text":"EHP11403"}}EHP11403     

社区儿童哮喘及过敏性疾病的环境影响因素分析

比较上海市徐汇区2013年和2020年儿童呼吸系统及过敏性疾病的发生状况,并了解其影响因素。

收集2013—2020年上海市环境空气质量监测数据并描述和比较,指标包括PM_2.5、PM₁₀、O₃、SO₂和NO₂。2013年和2020年9月对上海市徐汇区一所学校的3~5年级的学生分别开展1次横断面问卷调查,调查内容包括家庭环境、生活习惯、家族史、呼吸和过敏性疾病和症状的发生情况等。比较不同时间上海市大气污染变化情况及不同时间儿童呼吸及过敏性疾病发生情况的差异,并采用单因素分析、多因素分析方法对其影响因素进行分析。

共收到有效问卷1 398份（2013年705份,2020年693份）。2020年大气PM_2.5、PM₁₀、O₃、SO₂和NO₂的年均浓度相较2013年显著改善。徐汇区2013年支气管哮喘、支气管炎、持续咳嗽和持续咳痰的患病率和症状发生率高于2020年（均 P<0.05）。多因素分析显示,重污染年份、男生、父母有哮喘病史和过敏史、父母文化程度越高以及家中存在过敏原是支气管哮喘、支气管炎、变应性鼻炎以及特应性湿疹发生的影响因素（均P<0.05）;父母有过敏史、家人吸烟频率较高以及家中存在过敏原是持续咳嗽和持续咳痰发生的影响因素（均P<0.05）。

上海市大气污染2020年比2013年有所减轻,儿童支气管哮喘和支气管炎患病率有所下降;室内外环境、家族史、生活习惯等因素与儿童呼吸系统和过敏性疾病发生相关。

     

Mini-dCas13X–mediated RNA editing restores dystrophin expression in a humanized mouse model of Duchenne muscular dystrophy

Approximately 10% of monogenic diseases are caused by nonsense point mutations that generate premature termination codons (PTCs), resulting in a truncated protein and nonsense-mediated decay of the mutant mRNAs. Here, we demonstrate a mini-dCas13X–mediated RNA adenine base editing (mxABE) strategy to treat nonsense mutation–related monogenic diseases via A-to-G editing in a genetically humanized mouse model of Duchenne muscular dystrophy (DMD). Initially, we identified a nonsense point mutation (c.4174C>T, p.Gln1392*) in the DMD gene of a patient and validated its pathogenicity in humanized mice. In this model, mxABE packaged in a single adeno-associated virus (AAV) reached A-to-G editing rates up to 84% in vivo, at least 20-fold greater than rates reported in previous studies using other RNA editing modalities. Furthermore, mxABE restored robust expression of dystrophin protein to over 50% of WT levels by enabling PTC read-through in multiple muscle tissues. Importantly, systemic delivery of mxABE by AAV also rescued dystrophin expression to averages of 37%, 6%, and 54% of WT levels in the diaphragm, tibialis anterior, and heart muscle, respectively, as well as rescued muscle function. Our data strongly suggest that mxABE-based strategies may be a viable new treatment modality for DMD and other monogenic diseases.     

MRI动态对比增强成像及DWI联合应用对进展期食管癌同步放化疗早期疗效评估的价值

目的 探讨MRI动态对比增强成像（DCE-MRI）联合磁共振弥散加权成像（DWI-MRI）在进展期食管癌同步放化疗患者早期疗效评价中的应用价值。 方法 回顾性分析2018年2月至2021年6月于江苏省肿瘤医院确诊的48例进展期食管癌患者放化疗治疗前、治疗第2~3周（治疗中）DWI-MRI和DCE-MRI的影像学及临床资料,其中男性24例、女性24 例,年龄（67.1±7.7）岁。根据实体瘤疗效评价标准（RESIST）（1.1版）将患者分为治疗有效组和无效组。采用配对样本t检验、Wilcoxon秩和检验比较容量转移常数（Ktrans）、速率常数（Kep）、血管外细胞外间隙容积比（Ve）、表观扩散系数（ADC）、Ktrans的差值（ΔKtrans）、Kep的差值（ΔKep）、Ve的差值（ΔVe）、ADC差值（ΔADC）在治疗前、治疗中的差异;采用独立样本t检验、Mann-Whitney U 检验比较Ktrans、Kep、Ve、ADC、ΔKtrans、ΔKep、ΔVe、ΔADC在治疗有效组、无效组之间的差异;计数资料的比较采用χ2检验或Kruskal-Wallis检验;采用单因素Logistic回归分析预测疗效的相关因素;采用多因素Logistic回归分析筛选出独立影响因素并建立疗效的预测模型,利用受试者工作特征（ROC）曲线评估模型的预测效能。 结果 48例患者中,治疗有效组32例、无效组16例。治疗有效组治疗前Ktrans高于无效组[0.42（0.33,0.55） min−1对0.29（0.25,0.42） min−1],差异有统计学意义（Z=−2.909,P=0.007）;治疗有效组治疗前ADC高于无效组[（1.42±0.38）×10−3 mm2/s对（1.14±0.21）×10−3 mm2/s）]、治疗中ADC高于无效组[（2.30±0.43）×10−3 mm2/s对（1.63±0.44）×10−3 mm2/s]、ΔADC高于无效组[（0.86±0.39）×10−3 mm2/s对（0.45±0.49）×10−3 mm2/s],且差异均有统计学意义（t=−3.244、 −5.013、−3.068,均P<0.05）。单因素Logistic回归分析结果显示,治疗前Ktrans（OR=1.093,95%CI：1.021~1.171）、ΔKtrans（OR=0.968,95%CI：0.939~0.997）、治疗前ADC（OR=18.304,95%CI：1.606~208.659）、治疗中ADC（OR=22.678,95%CI：3.920~131.211）、ΔADC（OR=9.996,95%CI：1.802~55.440）是同步放化疗疗效的影响因素（均P<0.05）;多因素二元Logistic回归分析结果显示,治疗中ADC是影响疗效的独立预测因素（95%CI：1.331~81.220,AUC=0.892,P=0.026）。 结论 DCE-MRI联合DWI-MRI参数预测模型可对进展期食管癌同步放化疗治疗效果进行早期评价。     

蔓荆子提取物对小鼠造血系统辐射损伤的防护作用

目的 探讨蔓荆子提取物对小鼠造血系统辐射损伤的防护作用。 方法 （1）体外细胞实验：提取小鼠骨髓细胞,将骨髓细胞分为对照组、蔓荆子组、照射组和蔓荆子+照射组,蔓荆子组的给药浓度为0.01 mg/ml和0.001 mg/ml,蔓荆子+照射组的给药浓度为0.001 mg/mL,照射组和蔓荆子+照射组细胞经1 Gy照射。使用酶标仪检测细胞活力,异硫氰酸荧光素（FITC）通道检测细胞的活性氧（ROS）水平,FITC和藻红蛋白（PE）通道检测细胞的凋亡水平。（2）体内实验：采用简单随机抽样法将15只C57BL/6小鼠分为对照组（n=5）、照射组（n=5）和蔓荆子+照射组（n=5）。对照组小鼠进行假照射（0 Gy）,照射组和蔓荆子+照射组小鼠进行一次性2 Gy全身照射。将蔓荆子提取物用二甲基亚砜（DMSO）配制为 500 mg/ml 的蔓荆子溶液,灌胃前用生理盐水稀释,蔓荆子+照射组小鼠于照射前给予蔓荆子提取物（400 mg/kg）0.2 ml,连续给药7 d,照射后10 d处死小鼠。使用全自动血液分析仪分别对外周血血细胞和骨髓有核细胞（BMNC）计数,使用流式细胞仪分析造血干/祖细胞的数量和百分比,检测骨髓造血细胞内ROS水平、人磷酸化组蛋白H2A变异体（γH2AX）和磷酸化的p38（pp38）的表达。符合正态分布的计量资料的2组间比较采用独立样本t检验（方差齐）。 结果 （1）体外细胞实验：与照射组比较,0.001 mg/mL蔓荆子+照射组的骨髓细胞活力明显提高（585 485.00±37 335.80对460 384.55±53 786.37）,ROS水平降低（12 260.67±232.34对17 969.67±467.24）,凋亡细胞百分比显著降低[（28.97±0.32）% 对 （35.33±0.35）%],且差异均有统计学意义（t=4.245、18.950、23.161,均P<0.01）。（2）体内实验：与照射组相比,蔓荆子+照射组小鼠的BMNC数量[（23.34±3.01）×106个/只对（16.73±2.57）×106个/只]、白细胞数量[（2.80±0.35）×109个/L对（2.21±0.24）×109个/L]、红细胞数量[（10.54±0.51）×1012个/L对（9.68±0.26）×1012个/L]、血小板数量[（339.80±49.42）×109个/L对（289.40±54.08）×109个/L]和血红蛋白含量[（139.20±3.66） g/L对（129.20±3.87） g/L]均升高,且差异均有统计学意义（t=2.582、2.824、2.999、1.376、9.739,均P<0.01）。与照射组比校,蔓荆子+照射组小鼠造血祖细胞的数量[（34916.03±697.36）个/只对（26388.04±241.78）个/只]和百分比[（29.83±4.32）%对（22.76±2.20）%]升高,造血干细胞的数量[（2 074.00±23.12）个/只对（929.40±166.52）个/只]升高,且差异均有统计学意义（t=5.423、9.171、3.175,均P<0.01）;造血干/祖细胞中的ROS水平下降[（7 750.20±589.05）对（8 515.20±1 036.46）,（9 360.20±831.97）对（10 291.40±767.57）],差异均无统计学意义（t=1.435、1.839,P=0.189、0.103）;造血干/祖细胞中γH2AX的表达降低（693.20±4.82对751.60±32.72）, 且差异有统计学意义（t=3.064,P<0.01）;造血干/祖细胞中pp38表达降低（1 181.20±11.28对1 183.60±49.70,1 411.20±50.25对1 424.40±80.95）,差异均无统计学意义（t=0.105、0.765, P=0.014、0.310）。 结论 蔓荆子提取物通过降低造血细胞的氧化应激和抑制造血干细胞内的DNA损伤来达到辐射防护效果。     

Microfluidic study of retention and elimination of abnormal red blood cells by human spleen with implications for sickle cell disease

The spleen clears altered red blood cells (RBCs) from circulation, contributing to the balance between RBC formation (erythropoiesis) and removal. The splenic RBC retention and elimination occur predominantly in open circulation where RBCs flow through macrophages and inter-endothelial slits (IESs). The mechanisms underlying and interconnecting these processes significantly impact clinical outcomes. In sickle cell disease (SCD), blockage of intrasplenic sickled RBCs is observed in infants splenectomized due to acute splenic sequestration crisis (ASSC). This life-threatening RBC pooling and organ swelling event is plausibly triggered or enhanced by intra-tissular hypoxia. We present an oxygen-mediated spleen-on-a-chip platform for in vitro investigations of the homeostatic balance in the spleen. To demonstrate and validate the benefits of this general microfluidic platform, we focus on SCD and study the effects of hypoxia on splenic RBC retention and elimination. We observe that RBC retention by IESs and RBC–macrophage adhesion are faster in blood samples from SCD patients than those from healthy subjects. This difference is markedly exacerbated under hypoxia. Moreover, the sickled RBCs under hypoxia show distinctly different phagocytosis processes from those non-sickled RBCs under hypoxia or normoxia. We find that reoxygenation significantly alleviates RBC retention at IESs, and leads to rapid unsickling and fragmentation of the ingested sickled RBCs inside macrophages. These results provide unique mechanistic insights into how the spleen maintains its homeostatic balance between splenic RBC retention and elimination, and shed light on how disruptions in this balance could lead to anemia, splenomegaly, and ASSC in SCD and possible clinical manifestations in other hematologic diseases.

The human spleen is a unique organ that plays an important role in our immune and circulatory systems. The spleen is composed primarily of two distinct functional regions, the red pulp and the white pulp, which are intermingled by the marginal/perifollicular zone (1). It contains complex vascular pathways involving direct and indirect connections. Direct connections exist between the fast perifollicular microcirculation and venous sinuses drained in splenic veins (“closed circulation”), whereas indirect connections exist between red pulp arterioles and veins through the reticular meshwork (“open circulation”) and across the wall of sinuses (1). As much as about 80% of the spleen parenchyma is populated with the red pulp, which mainly comprises the vascular sinuses and cords of Billroth (1, 2). Approximately 3 to 10% of blood from cardiac output flows through the spleen, and about 10% of splenic inflow passes through slow open circulation in the red pulp (1, 3–5).Splenic filtration of abnormal red blood cells (RBCs) is predominately performed in the open circulation, through macrophage-rich zones (M-filter) and across splenic inter-endothelial slits (IESs) in the wall of sinuses (S-filter), as shown in Fig. 1A. The specialized elongated shape of littoral cells in the splenic sinuses and their three-dimensional (3D) barrel-like structure impose sub-micrometer scale physical barriers or constraints on RBCs navigating the open circulation (6). Prior to returning to the systemic circulation through the IESs across the spleen, circulating RBCs are checked for surface integrity by a scattered collection of resident macrophages (7). These two structural and functional spleen filters, S-filter and M-filter (Fig. 1B), sustain the remarkable capacity of the spleen to retain and destroy abnormal RBCs. Consequently, they contribute to the fine balance between RBC production in the bone marrow and the removal of abnormal RBCs from the blood circulation (1).Open in a separate windowFig. 1.Splenic filtration of altered RBCs. (A) Schematic diagram of blood circulation through splenic red pulp, including closed circulation and open circulation. The splenic filtration of altered RBCs is achieved in the open circulation in the red pulp, through macrophages (M-filter) and the splenic IESs (S-filter). (B) Schematic diagram of the oxygen gradient near the sinus. The two structural and functional spleen filters, the S-filter and M-filter, respectively, are modeled in vitro using the S-Chip and M-Chip, respectively. Created with BioRender.com.Healthy human RBCs (AA RBCs) have an average life span of 100 to 120 d (8), indicating that about 1% of the RBCs are recycled each day by the human body (9). Senescent RBCs typically have reduced deformability (10) and send signals to macrophages by expressing higher phosphatidylserine (PS), higher band-3, and reduced CD47 levels (11, 12), on their external cell surface. Senescent RBCs could exhibit a higher propensity to be sequestered at the IESs due to their reduced deformability and then cleared by macrophages, or trapped by adhesion and phagocytosed in the meshwork (13). Here, a balance between RBC retention rate and RBC elimination rate (by post-retention processing) should be dynamically maintained to ascertain homeostasis. Such homeostatic balance, however, can be severely disrupted due to hemolytic disorders, resulting in serious, and sometimes life-threatening, complications such as splenomegaly and/or hypersplenism (14). As a result, the RBC retention rate can significantly surpass the RBC post-retention elimination rate in the spleen. It is, therefore, important to investigate systematically and quantitatively both the RBC retention rate and the elimination rate in the spleen, and to compare their relative changes, as a function of disease state, with the baseline condition of healthy hemostasis.The spleen is generally in a hypoxic (low oxygen level) condition owing to its slow and open blood circulation in the red pulp (see the brief review of splenic oxygen level and transit time/velocity of RBCs in SI Appendix, Table S2). An oxygen gradient exists in the spleen from locations nearest to the arteriolar end of capillaries to the distal locations in the proximity of the IESs, as shown schematically in Fig. 1B (15). Under normal circumstances, hypoxia is mild due to continuous oxygen delivery by the RBCs through splenic circulation. However, it deepens with the reduction in oxygen delivery arising from the obstruction of RBC flow or anemia in many hemolytic blood disorders. For instance, in sickle cell disease (SCD), such obstruction/anemia-induced local hypoxia may in turn trigger sickling of homozygous sickle cell disease (HbSS) RBCs (SS RBCs) and subsequently lead to further reduction in deformability and increase in the expression of adhesion molecules (16, 17). Therefore, sickled RBCs have a higher propensity to be retained by the venous sinuses as well as cords of Billroth, thereby contributing further to a reduction in the oxygen level in the spleen (18). The splenic retention of SS RBCs depends on a trade-off between the local oxygen level (which determines the sickling kinetics) and the transit time of RBCs through the spleen (19). Excessive retention of stiff and sickled SS RBCs in the patient’s spleen has been considered a dominant cause of acute splenic sequestration crisis (ASSC), a life-threatening complication, in SCD (17, 20, 21). This process might involve a vicious cycle: the more RBCs the spleen traps, the larger the spleen grows, and the larger the spleen grows, the deeper the hypoxia is, resulting in more and more sickled SS RBCs that are consequently being trapped and destroyed. Indeed, following splenectomy in young SCD children with still functional spleen, sickled RBCs have been found retained and congested upstream of IESs during ASSC (17, 22, 23). On the other hand, surface modulations such as PS externalization (24), decreased levels of CD47 (25), and elevated binding of autologous immunoglobulin (26), as well as increased membrane rigidity of sickled RBCs may also promote the retention and elimination of SS RBCs by the splenic macrophages (27–29). From these considerations, we postulate that both increased mechanical retention and hyperactive phagocytosis elimination of abnormal RBCs can exacerbate significantly under some extreme conditions such as hypoxia in SCD. These factors could, in turn, play a key role in disrupting the homeostatic balance thereby causing spleen dysfunction in hemolytic disorders.Recent in vitro studies based on microfluidic spleen-on-a-chip platforms, which simulate the micro-constrictions of IESs and hydrodynamic conditions, have advanced the functional study of RBC filtration in the spleen (30–33). However, to our knowledge, no prior in vitro assays have effectively integrated a controlled gaseous microenvironment within a microfluidic system to enable the quantitative investigation of the hypoxic effect on splenic retention and post-retention elimination of RBCs, especially for SS RBCs. Moreover, there is a compelling need for an in vitro assay that elucidates the mechanisms underlying the interaction of RBCs with splenic phagocytes during the low-velocity microcirculation through the red pulp. Most existing erythrophagocytosis (RBC elimination) assays measure phagocytic activity in a static condition, which does not faithfully replicate in vivo conditions (27, 28). To this end, the development and validation of an oxygen-mediated in vitro assay for investigating the kinetics of both splenic retention of RBCs and erythrophagocytosis under hypoxia are critically needed for a better understanding of the mechanisms responsible for splenic functions in physiology and disease.Here we present a general microfluidic platform to systematically probe the retention and elimination functions undertaken by IESs and macrophages in the human spleen, by developing and validating two functional modules of an oxygen-mediated spleen-on-a-chip. This platform entails the S-Chip and the M-Chip, which model the S-filter for RBC retention through splenic IESs and the M-filter for RBC adhesion and elimination by splenic resident macrophages, respectively. While the microfluidic platform and assays presented in this work can, by design, potentially provide mechanistic insights into a wide spectrum of hereditary and acquired human diseases, we focus particular attention here on the study of homeostatic processes in SCD. We make comparisons with healthy subjects as a negative control group. We additionally use heated AA RBCs as a positive control, while considering it as a generic model for exploring different controlled concentrations of altered RBCs in hemolytic disorders. We demonstrate that our microfluidic platform can also be used to mimic in vitro the two major components of the spleen filtering unit, namely surface sensing by macrophages and mechanical sensing by splenic IESs under controlled oxygen pressure. We further show that this approach enables systematic investigations of the cellular mechanisms underlying anemia and ASSC in SCD, while also providing potential pathways to explore, with appropriate modifications, splenomegaly and hypersplenism in other diseases such as Plasmodium falciparum malaria.