糖尿病多形核白细胞吞噬功能的改变

目的 研究正常人及糖尿病患者多形核白细胞（polymorphonuclear leukocytes,PMNLs)吞噬功能的改变及钙通道阻滞剂对其的影响。方法 应用过氧化氢释放法测定白细胞吞噬功能,同时研究PMNLs细胞外不同浓度糖环境及钙通道阻滞剂对细胞吞噬功能的影响。结果 糖尿病患者的PMNLs吞噬功能较正常人低下。体外培养基葡萄糖浓度增高,吞噬功能越差,硝苯啶可明显改善糖尿病患者PMNLs的吞噬功能。结论 推测葡萄糖可能是通过激活L型钙通道引起细胞内游离钙浓度升高,从而影响吞噬功能,而硝苯啶可阻断该通道,恢复吞噬功能。     

静脉注射免疫球蛋白对急性川崎病患儿淋巴细胞凋亡的影响

通过观察静脉注射免疫球蛋白（ＩＶＩＧ）对川崎病（ＫＤ）患儿淋巴细胞凋亡（ＡＰＯ）的影响，进一步探讨ＩＶＩＧ对免疫性疾病的作用机理。对２６例川崎病患儿和２０名健康儿童外周血单个核细胞（ＰＢＭＣ）经抗－ＣＤ３单克隆抗体刺激培养不同时间（０，１２，２４，４８，７２小时）ＡＰＯ百分率和ＤＮＡ片断化分析，２６例患儿随机分为两组，阿司匹林＋ＩＶＩＧ治疗组（ｎ＝１６）和阿司匹林治疗组（ｎ＝１０），并对ＰＢＭＣ经植物血凝素（ＰＨＡ）刺激淋巴细胞增殖反应进行了观察。结果：ＫＤ患儿ＡＰＯ百分率和ＤＮＡ片断化较正常儿童明显降低（Ｐ＜０．００１）和延迟；ＩＶＩＧ治疗后，降低的ＡＰＯ百分率和延迟的ＤＮＡ片断化被逆转，同时与单用阿司匹林组比较，临床症状明显改善。淋巴细胞增殖反应下调（Ｐ＜０．００１）。外周血淋巴细胞ＡＰＯ下调可能参与了ＫＤ的发病。ＩＶＩＧ治疗ＫＤ的机理可能部分归于对被抑制的淋巴细胞ＡＰＯ的逆转。ＩＶＩＧ对其它淋巴细胞凋亡不足的自身免疫性疾病治疗可能存在同样机理。     

地塞米松对小梁细胞粘附及吞噬功能的影响

目的：探讨地塞米松对小梁细胞的粘附及吞噬功能的影响。方法：不同浓度地塞米松(10^-7M，10^-6M，10^-5M)处理体外培养的牛眼小梁细胞3d，消化、漂洗后加入用不同的细胞外基质(Extracellular matrix，ECM)包被的培养板中，37℃孵育90min后．采用甲基噻唑基四唑(Methyl thiazolyl tetrazolium，MW)法测定各组吸光度值反应粘附细胞的量；另外，以乳胶微球为标记，观察不同浓度的地塞米松对小梁细胞吞噬功能的影响。结果：与对照组比较，三种浓度的地塞米松均对小梁细胞与ECM粘附有抑制作用．且呈浓度依赖性；对小梁细胞的吞噬功能亦呈现浓度依赖性抑制作用。结论：地塞米松对小梁细胞的粘附及吞噬功能有抑制作用，抑制小梁细胞的粘附及吞噬功能可能是皮质类固醇性青光眼的发病原因之一。     

Heme oxygenase1 (HSP-32) is induced in myelin-phagocytosing Schwann cells of injured sciatic nerves in the rat

Schwann cells participate in myelin phagocytosis in the early stage of Wallerian degeneration, prior to the recruitment of macrophages. This is the first report that Schwann cells induce heme oxygenase-1 (HO-1), a 32-kDa heat shock protein, only when they have transformed into myelin-phagocytosing cells from myelinating cells (days 2-3) immediately after crush injury of rat sciatic nerves. Double immunofluorescent labelling for HO-1 and transferrin receptors revealed that HO-1-immunoreactive Schwann cells also expressed transferrin receptors suggesting activation of iron metabolism. The transient induction of HO-1 in Schwann cells may contribute to the adaptive function in an altered environment when the cells have lost contact with axons, and may play a crucial role in the ensuing regeneration.     

疏通化纤丸对小鼠免疫功能的调节作用

目的观察疏通化纤丸对小鼠免疫功能的影响。方法以地塞米松引起小鼠免疫功能低下 ,以左旋咪唑作阳性对照 ,测定疏通化纤丸对免疫功能正常和低下小鼠巨噬细胞吞噬功能、血清溶血素含量以及ConA诱导T淋巴细胞增殖的作用。结果疏通化纤丸能明显提高免疫功能正常和低下小鼠的廓清指数、吞噬指数 ,能促进ConA诱导的正常小鼠脾淋巴细胞的增殖 ,而左旋咪唑仅对免疫低下的小鼠才有提高以上指标的功能。结论疏通化纤丸对机体免疫功能具有显著的提高作用。     

Simultaneous flow cytometric measurement of antigen attachment to phagocytes and phagocytosis

The current available assays cannot differentiate the stages of phagocytosis. We, therefore, established methods for concurrent detection of antigen attachment and engulfment by phagocyte using latex beads coated with lipopolysaccharide, rabbit IgG, and carboxyfluorescein diacetate succinimidyl ester. The generated beads were incubated with whole blood at 37°C for 1 hr and stained with PE-Cy5.5 anti-rabbit IgG antibody. By flow cytometry, attachment and phagocytic processes could be detected, simultaneously. The established method is a valuable tool for diagnosis of phagocytic disorder and study of molecules involved in phagocytosis.     

Magnesium treatment of diuretic-induced hyponatremia with a preliminary report of a new aldosterone-antagonist.

Long-term diuretic treatment of patients with congestive heart failure is often complicated by hyponatremia and resistance to diuretic treatment, as well as by hypokalemia. Less widely recognized is the increase in intracellular sodium in the presence of hyponatremia, and loss of magnesium, caused by sustained diuretic therapy. Because the sodium pump, which maintains intracellular sodium and potassium against a concentration gradient, is dependent on optimal magnesium levels, we have investigated the influence of magnesium infusions on serum and skeletal muscle levels of sodium and potassium in congestive heart failure patients with electrolyte disturbances. Because aldosteronism, such as accompanies the disease and diuretic treatment, increases intracellular sodium, we have measured intracellular sodium and potassium in six patients given a new aldosterone antagonist (canrenone). It lowered the muscle sodium and raised the muscle potassium and magnesium, and slightly raised the serum sodium. The magnesium infusions, given to eight patients, significantly increased the serum sodium and lowered the muscle sodium levels, and normalized both serum and subnormal muscle potassium levels.     

Central nervous system diseases related to pathological microglial phagocytosis

Microglia are important phagocytes of the central nervous system (CNS). They play an important role in protecting the CNS by clearing necrotic tissue and apoptotic cells in many CNS diseases. However, recent studies have found that microglia can phagocytose parts of neurons excessively, such as the neuronal cell body, synapse, or myelin sheaths, before or after the onset of CNS diseases, leading to aggravated injury and impaired tissue repair. Meanwhile, reduced phagocytosis of synapses and myelin results in abnormal circuit connections and inhibition of remyelination, respectively. Previous studies focused primarily on the positive effects of microglia phagocytosis, whereas only a few studies have focused on the negative effects. In this review, we use the term "pathological microglial phagocytosis" to refer to excessive or reduced phagocytosis by microglia that leads to structural or functional abnormalities in target cells and brain tissue. The classification of pathological microglial phagocytosis, the composition, and activation of related signaling pathways, as well as the process of pathological phagocytosis in various kinds of CNS diseases, are described in this review. We hypothesize that pathological microglial phagocytosis leads to aggravation of tissue damage and negative functional outcome. For example, excessive microglial phagocytosis of synapses can be observed in Alzheimer's disease and schizophrenia, leading to significant synapse loss and memory impairment. In Parkinson's disease, ischemic stroke, and traumatic brain injury, excessive microglial phagocytosis of neuronal cell bodies causes impaired gray matter recovery and sensory dysfunction. We therefore believe that more studies should focus on the mechanism of pathological microglial phagocytosis and activation to uncover potential targets of therapeutic intervention.     

Comparative Efficiency and Impact on the Activity of Blood Neutrophils Isolated by Percoll,Ficoll and Spontaneous Sedimentation Methods

Studies on the role of cells in physiological and pathological processes generally require isolation of some populations, such as neutrophils. In the literature, several methods used for isolating neutrophils are described; however, there is no consensus on the best technique to be used in cell functional studies. The present study compares the efficiency and impact on the chemotactic and phagocytic activity of neutrophils isolated from blood by three different methods: Percoll and Ficoll density centrifugation gradients and spontaneous sedimentation technique. The neutrophil chemotaxis, stimulated with lipopolysaccharide (LPS), autologous serum or homologous serum, was determined by using Boyden chambers. The phagocytic capacity was assessed by ingestion of zimosan particles, and digestion phase was analyzed by nitroblue tetrazolium test (NBT). The results obtained from neutrophil isolation by Percoll and Ficoll density gradients, as compared to spontaneous sedimentation technique, showed similar degrees of cell yields and higher purity; however, these methods affected neutrophil responsiveness, accompanied by elevated chemotaxis and reduced chemotactic capacity to respond to subsequent stimulation. Neutrophil isolation by spontaneous sedimentation, in contrast, did not affect cellular activity and resulted in cell preparation with high number of neutrophils. Although neutrophil phagocytosis results were similar between the different methods, digestion phase of phagocytosis was significantly enhanced after LPS-stimulation, only in the neutrophils isolated by spontaneous sedimentation technique. In conclusion, the present study shows that isolation of blood neutrophils by the spontaneous sedimentation technique is appropriate for the assessment of cellular activity, since it neither primes or activates the neutrophils nor does it affect their functional responsiveness.     

Immune-pineal axis protects rat lungs exposed to polluted air

Environmental pollution in the form of particulate matter <2.5 μm (PM_2.5) is a major risk factor for diseases such as lung cancer, chronic respiratory infections, and major cardiovascular diseases. Our goal was to show that PM_2.5 eliciting a proinflammatory response activates the immune-pineal axis, reducing the pineal synthesis and increasing the extrapineal synthesis of melatonin. Herein, we report that the exposure of rats to polluted air for 6 hours reduced nocturnal plasma melatonin levels and increased lung melatonin levels. Melatonin synthesis in the lung reduced lipid peroxidation and increased PM_2.5 engulfment and cell viability by activating high-affinity melatonin receptors. Diesel exhaust particles (DEPs) promoted the synthesis of melatonin in a cultured cell line (RAW 264.7 cells) and rat alveolar macrophages via the expression of the gene encoding for AANAT through a mechanism dependent on activation of the NFκB pathway. Expression of the genes encoding AANAT, MT1, and MT2 was negatively correlated with cellular necroptosis, as disclosed by analysis of Gene Expression Omnibus (GEO) microarray data from the human alveolar macrophages of nonsmoking subjects. The enrichment score for antioxidant genes obtained from lung gene expression data (GTEx) was significantly correlated with the levels of AANAT and MT1 but not the MT2 melatonin receptor. Collectively, these data provide a systemic and mechanistic rationale for coordination of the pineal and extrapineal synthesis of melatonin by a standard damage-associated stimulus, which activates the immune-pineal axis and provides a new framework for understanding the effects of air pollution on lung diseases.