Phagocytosis of inert particles in Locusta migratoria and Galleria mellonella: Study of ultrastructure and clearance

Inert particles (iron saccharate or latex beads) injected in the haemocoel of Locusta migratoria, are taken up by pericardial cells (iron saccharate only), reticular cells of the haemopoietic tissue and certain haemocytes: plasmatocytes and coagulocytes; these two haemocyte types are also the main phagocytic blood cells in Galleria mellonella.Necrosis of phagocytic haemocytes, following injection of an overdose of iron saccharate, explains the profound modifications of the haemogram observed during the first 24 hr following injection; the macrophagic evolution of reticular cells slows down the haemopoietic differentiation of these cells and explains the long term disturbances of the blood picture.Clearance of latex beads injected in larvae of Locusta complies to an exponential function of time; we can determine a granulopectic index which will permit comparisons to be made between clearance of inert and of ‘antigenic-like’ particles.     

小骨窗显微手术治疗基底节区高血压脑出血的效果分析及对血清CCCK-18、CTRP-3水平的影响

目的:探讨小骨窗显微手术治疗基底节区高血压脑出血的效果及对血清gaspase切割的细胞角蛋白18(CCCK-18)、补体C1q肿瘤坏死因子相关蛋白3(CTRP-3)水平的影响。方法:选取2016年5月至2018年5月我院收治的160例基底节区高血压脑出血患者,按照随机数表法将其分为观察组(n=82)和对照组(n=78)。对照组采用传统大骨瓣开颅术治疗,观察组采用小骨窗显微手术治疗。观察和比较两组的临床疗效,血肿清除率、术中出血量、术后意识恢复时间、住院时间,治疗前后NIHSS、ADL评分、血清CCCK-18、CTRP-3水平的变化及并发症的发生情况。结果:治疗后,观察组总有效率显著高于对照组[95.12%vs. 79.48%](P0.05);血肿清除率、术中出血量、术后意识恢复时间、住院时间均显著优于对照组[(93.62±3.58)%vs.(85.40±2.19)%,(92.47±12.56)mL vs.(189.25±26.47) mL,(2.01±0.58) d vs.(8.69±2.03) d,(13.39±2.08) d vs.(19.45±3.76) d](P0.05);NIHSS评分显著低于对照组[(9.76±1.42)分vs.(20.57±3.26)分](P0.05);ADL评分显著高于对照组[(86.42±8.64)分vs.(75.39±7.02)分](P0.05);血清CCCK-18水平显著低于对照组[(201.76±32.59) U/L vs.(237.57±39.20) U/L,(29.59±5.19) ng/mL vs.(42.97±7.94)ng/mL](P0.05);CTRP-3水平显著高于对照组[(289.59±35.19)ng/mL vs.(232.97±27.94)ng/mL](P0.05);并发症总发生率显著低于对照组[3.65%(3/82) vs. 14.10%(11/78)](P0.05)。结论:小骨窗显微手术治疗基底节区高血压脑出血的疗效显著,可更有效清除血肿,缓解血肿压迫,改善神经功能,减少继发性损伤,安全性高,可能与其降低血清CCCK-18水平及升高CTRP-3水平有关。     

优化两步输注美罗培南联合参麦注射液对重症感染患者血清感染指标、细菌清除率和T淋巴细胞亚群的影响

目的:探讨优化两步输注美罗培南联合参麦注射液对重症感染患者血清感染指标、细菌清除率和T淋巴细胞亚群的影响。方法:选取2017年1月-2018年10月在我院重症医学科(ICU)住院的153例重症感染患者,按随机数字表法将患者分为传统输注美罗培南组(A组,54例)、优化两步输注美罗培南组(B组,49例)、优化两步输注美罗培南联合参麦注射液组(C组,50例)。比较治疗后三组患者的总体疗效、血清感染指标和T淋巴细胞亚群水平及不良反应发生情况。结果:B组、C组的临床有效率、细菌清除率、28天生存率高于A组(P<0.05);B组、C组机械通气时间、ICU住院时间、总住院时间少于A组,且C组少于B组(P<0.05);治疗后B组、C组CD3⁺、CD4⁺、CD4⁺/CD8⁺高于A组,且C组高于B组(P<0.05);B组、C组CD8⁺、白细胞计数(WBC)、降钙素原(PCT)、C-反应蛋白(CRP)水平低于A组,且C组低于B组(P<0.05)。三组患者不良反应发生率比较无差异(P>0.05)。结论:优化两步输注美罗培南联合参麦注射液治疗重症感染患者疗效确切,可提高细菌清除率,改善患者免疫状态,促进患者康复。     

The ins and outs of phospholipid asymmetry in the plasma membrane: roles in health and disease

A common feature of all eukaryotic membranes is the non-random distribution of different lipid species in the lipid bilayer (lipid asymmetry). Lipid asymmetry provides the two sides of the plasma membrane with different biophysical properties and influences numerous cellular functions. Alteration of lipid asymmetry plays a prominent role during cell fusion, activation of the coagulation cascade, and recognition and removal of apoptotic cell corpses by macrophages (programmed cell clearance). Here we discuss the origin and maintenance of phospholipid asymmetry, based on recent studies in mammalian systems as well as in Caenhorhabditis elegans and other model organisms, along with emerging evidence for a conserved role of mitochondria in the loss of lipid asymmetry during apoptosis. The functional significance of lipid asymmetry and its disruption during health and disease is also discussed.     

Determinants of serum levels of surfactant proteins A and B and Clara cell protein CC16

Increased leakage of surfactant proteins A and B (SP-A and SP-B) and Clara cell secretory protein (CC16) from the air spaces into the circulation occurs in a range of respiratory conditions. However, circulating levels depend not only on the rate of entry into the circulation, but also on the rate of clearance. In order to clarify the role of the kidney in the clearance of these proteins, serum levels were related to markers of glomerular filtration in 54 non-smoking patients with varying degrees of renal dysfunction, none of whom had respiratory disease or were receiving dialysis at the time of sampling. Serum SP-A was related to SP-B (r=0.53, p<0.001) and to CC16 (r=0.33, p<0.02). Similarly, SP-B was related to CC16 (r=0.39, p<0.004). Stepwise multiple linear regression analysis suggested that serum SP-A and SP-B are influenced by age (～20 and ～25% of variance, respectively), whereas CC16 is determined by renal function and, to a lesser extent, by body weight (～63% of variance in total). We conclude that CC16 is cleared from blood by the renal route, whereas SP-A and SP-B are not. Serum SP-A and SP-B are influenced by age, which we speculate reflects increased damage to the alveolocapillary barrier.     

Kir4.1-mediated spatial buffering of K+: Experimental challenges in determination of its temporal and quantitative contribution to K+ clearance in the brain

Neuronal activity results in release of K⁺ into the extracellular space of the central nervous system. If the excess K⁺ is allowed to accumulate, neuronal firing will be compromised by the ensuing neuronal membrane depolarization. The surrounding glial cells are involved in clearing K⁺ from the extracellular space by molecular mechanism(s), the identity of which have been a matter of controversy for over half a century. Kir4.1-mediated spatial buffering of K⁺ has been promoted as a major contributor to K⁺ removal although its quantitative and temporal contribution has remained undefined. We discuss the biophysical and experimental challenges regarding determination of the contribution of Kir4.1 to extracellular K⁺ management during neuronal activity. It is concluded that 1) the geometry of the experimental preparation is crucial for detection of Kir4.1-mediated spatial buffering and 2) Kir4.1 enacts spatial buffering of K⁺ during but not after neuronal activity.     

Effect of antigen binding affinity and effector function on the pharmacokinetics and pharmacodynamics of anti-IgE monoclonal antibodies

Modulating the binding affinities to IgE or changing the FcγR binding properties of anti-IgE antibodies offers an opportunity to enhance the therapeutic potential of anti-IgE antibodies, but the influence of increased affinity to IgE or reduced Fc effector function on the pharmacological properties of anti-IgE therapies remains unclear. Our studies were designed to characterize the pharmacokinetics, pharmacodynamics and immune-complex distribution of two high-affinity anti-IgE monoclonal antibodies, high-affinity anti-IgE antibody (HAE) 1 and 2, in mice and monkeys. HAE1, also known as PRO98498, is structurally similar to omalizumab (Xolair®), a humanized anti-IgE IgG1 marketed for the treatment of asthma, but differs by 9 amino acid changes in the complementarity-determining region resulting in a 23-fold improvement in affinity. HAE2 is similar to HAE1, but its Fc region was altered to reduce binding to Fcγ receptors. As expected given the decreased binding to Fcγ receptors, systemic exposure to pre-formed HAE2:IgE complexes in mice was greater (six-fold) and distribution to the liver lower (four-fold) compared with HAE1:IgE complexes. In monkeys, systemic exposure to HAE1 was similar to that previously observed for omalizumab in this species, but required comparatively lower serum drug concentrations to suppress free IgE levels. HAE2 treatment resulted in greater exposure and greater increase of total IgE, relative to HAE1, because of decreased clearance of HAE2:IgE complexes. Overall, these data suggest that increased binding affinity to IgE may provide a more effective therapeutic for asthma patients, and that retaining FcγR binding of the anti-IgE antibody is important for elimination of anti-IgE:IgE complexes.     

High throughput cross-interaction measures for human IgG1 antibodies correlate with clearance rates in mice

Although improvements in technology for the isolation of potential therapeutic antibodies have made the process increasingly predictable, the development of biologically active monoclonal antibodies (mAbs) into drugs can often be impeded by developability issues such as poor expression, solubility, and promiscuous cross-reactivity. Establishing early stage developability screening assays capable of predicting late stage behavior is therefore of high value to minimize development risks. Toward this goal, we selected a panel of 16 monoclonal antibodies (mAbs) representing different developability profiles, in terms of self- and cross-interaction propensity, and examined their downstream behavior from expression titer to accelerated stability and pharmacokinetics in mice. Clearance rates showed significant rank-order correlations to 2 cross-interaction related assays, with the closest correlation to a non-specificity assay on the surface of yeast. Additionally, 2 self-association assays correlated with each other but not to mouse clearance rate. This case study suggests that combining assays capable of high throughput screening of self- and cross-interaction early in the discovery stage could significantly lower downstream development risks.