小儿大叶性肺炎的病原菌分布与肺功能分级的相关性分析

目的分析小儿大叶性肺炎的病原菌分布与肺功能分级的相关性。方法选择我院收治的80例大叶性肺炎患儿,对所有患儿的肺部病原菌进行分离鉴定,并对病原菌分布与肺功能分级的相关性进行分析。结果革兰氏阳性菌检出率为18.75%,革兰氏阴性菌检出率为81.25%。随着肺功能等级的增高,革兰氏阴性菌检出率增高,而革兰氏阳性菌检出率降低(P<0.05)。金黄色葡萄球菌对ERY、CFZ、CRO耐药性分别为66.67%、75.00%、83.33%,鲍曼不动杆菌对AMP、ERY、CFZ耐药性分别为86.36%、68.18%、95.45%;大肠杆菌、肺炎克雷伯菌以及铜绿假单胞菌对AMP、GEN的耐药性≥45%。肺功能3、4级患儿的SP-A与AP1水平均显著低于1、2级患儿,且肺功能4级患儿显著低于3级患儿(P<0.05)。结论大叶性肺炎患儿的肺功能等级与病原菌分布以及血清SP-A与AP1水平具有一定的相关性。     

桔梗总皂苷对肺炎支原体感染大鼠肺组织SP-A的影响

目的:通过研究桔梗总皂苷对肺炎支原体(MP)感染大鼠肺部组织中肺表面活性蛋白A(SP-A)表达的影响,探讨其对肺炎支原体感染大鼠肺部组织可能的修复机制。方法:60只Wistar大鼠,雌雄各半,体重80~100 g,随机分为6组,每组10只。分别为空白组、模型组、阳性药(阿奇霉素)组(第1天为45 mg·kg-1,第2~5天为22.5 mg·kg-1)、桔梗总皂苷高、中、低(56,28,14 mg·kg-1)剂量组。采用肺炎支原体滴鼻法造模1次。造模后第2天开始ig给药,阿奇霉素给药5 d,桔梗总皂苷给药10 d后采集大鼠左肺及右肺组织中叶,常规HE染色,显微镜下观察肺组织病理改变,逆转录聚合酶链反应法(RTPCR)检测肺组织中SP-A mRNA的表达水平,采用SPSS 17.0软件对数据进行统计学分析。结果:病理结果显示:模型组与空白组比较,肺组织可见明显的肺间质炎症(P0.01);与模型组比较,阳性药组、桔梗总皂苷高、中、低剂量组的肺组织炎症较模型组明显减轻(P0.05);肺组织中SP-A mRNA的表达水平显示:与空白组比较,模型组的肺组织SP-A mRNA表达明显下调(P0.01),与模型组比较,阳性药组、桔梗总皂苷高、中剂量组SP-A mRNA表达上调(P0.05)桔梗总皂苷低剂量组无显著差异。结论:桔梗总皂苷能够改善MP感染大鼠肺部组织的炎症,且对肺部的修复作用可能是通过上调SP-A表达实现的。     

The concentration of surfactant protein-A in amniotic fluid decreases in spontaneous human parturition at term

Objective. The fetus is thought to play a central role in the onset of labor. Pulmonary surfactant protein (SP)-A, secreted by the maturing fetal lung, has been implicated in the mechanisms initiating parturition in mice. The present study was conducted to determine whether amniotic fluid concentrations of SP-A and SP-B change during human parturition.

Study design. Amniotic fluid SP-A and SP-B concentrations were measured with a sensitive and specific ELISA in the following groups of pregnant women: (1) mid-trimester of pregnancy, between 15 and 18 weeks of gestation (n = 29), (2) term pregnancy not in labor (n = 28), and (3) term pregnancy in spontaneous labor (n = 26). Non-parametric statistics were used for analysis.

Results. SP-A was detected in all amniotic fluid samples. SP-B was detected in 24.1% (7/29) of mid-trimester samples and in all samples at term. The median amniotic fluid concentrations of SP-A and SP-B were significantly higher in women at term than in women in the mid-trimester (SP-A term no labor: median 5.6 μg/mL, range 2.2–15.2 μg/mL vs. mid-trimester: median 1.64 μg/mL, range 0.1–4.7 μg/mL, and SP-B term no labor: median 0.54 μg/mL, range 0.17–1.99 μg/mL vs. mid-trimester: median 0 μg/mL, range 0–0.35 μg/mL; both p < 0.001). The median amniotic fluid SP-A concentration in women at term in labor was significantly lower than that in women at term not in labor (term in labor: median 2.7 μg/mL, range 1.2–10.1 μg/mL vs. term no labor: median 5.6 μg/mL, range 2.2–15.2 μg/mL; p < 0.001). There was no significant difference in the median amniotic fluid SP-B concentrations between women in labor and those not in labor (term in labor: median 0.47 μg/mL, range 0.04–1.32 μg/mL vs. term no labor: median 0.54 μg/mL, range 0.17–1.99 μg/mL; p = 0.2).

Conclusion. The amniotic fluid concentration of SP-A decreases in spontaneous human parturition at term.     

Glia–neuron interactions in the mammalian retina

The mammalian retina provides an excellent opportunity to study glia–neuron interactions and the interactions of glia with blood vessels. Three main types of glial cells are found in the mammalian retina that serve to maintain retinal homeostasis: astrocytes, Müller cells and resident microglia. Müller cells, astrocytes and microglia not only provide structural support but they are also involved in metabolism, the phagocytosis of neuronal debris, the release of certain transmitters and trophic factors and K⁺ uptake. Astrocytes are mostly located in the nerve fibre layer and they accompany the blood vessels in the inner nuclear layer. Indeed, like Müller cells, astrocytic processes cover the blood vessels forming the retinal blood barrier and they fulfil a significant role in ion homeostasis. Among other activities, microglia can be stimulated to fulfil a macrophage function, as well as to interact with other glial cells and neurons by secreting growth factors. This review summarizes the main functional relationships between retinal glial cells and neurons, presenting a general picture of the retina recently modified based on experimental observations. The preferential involvement of the distinct glia cells in terms of the activity in the retina is discussed, for example, while Müller cells may serve as progenitors of retinal neurons, astrocytes and microglia are responsible for synaptic pruning. Since different types of glia participate together in certain activities in the retina, it is imperative to explore the order of redundancy and to explore the heterogeneity among these cells. Recent studies revealed the association of glia cell heterogeneity with specific functions. Finally, the neuroprotective effects of glia on photoreceptors and ganglion cells under normal and adverse conditions will also be explored.     

模拟大气混合污染物对大鼠肺表面蛋白A影响

目的筛选敏感的生物标志物,探讨大气混合污染物对肺泡II型上皮细胞(AT-II)的损伤及其机制,为控制大气污染的危害提供理论依据。方法使用便携式PM2.5采样器和47mm玻璃纤维滤膜采集大气粉尘样品,制成生理盐水混悬液,实验大鼠气管注入混悬液及动态吸入SO2、NO2、CO混合气,制备大气混合污染物吸入动物模型,测定染毒不同时间血清及支气管肺泡灌洗液(BALF)中肺表面活性蛋白(SP-A)水平,肺组织中SP-A的mRNA及蛋白表达。结果染毒7 d组大鼠肺组织中SP-A mRNA表达为1.816±1.299,明显高于染毒1、30 d组(0.930±0.587;0.902±0.378)及对照组;染毒30 d组大鼠肺组织中SP-A表达吸光度值为0.385±0.068,明显低于染毒7 d组(0.438±0.069)及对照组;染毒30 d组大鼠BALF中SP-A水平为47.09±5.78,明显低于染毒1、7 d组(54.72±6.15;58.82±9.76)及对照组;染毒30 d组大鼠血清中SP-A水平明显高于染毒1、7 d组及对照组。结论 SP-A是反映AT-II功能受损严重程度的肺特异性指标。     

Surfactant Apoprotein A (SP-A) in Tracheal Aspirates of Newborn Infants with RDS

Human pulmonary surfactant contains four groups of apoproteins, SP-A, B, C and D. We determined the concentration of SP-A in the tracheal aspirate of newborn infants by a two-site simultaneous immunoassay with monoclonal antibodies, and used this assay to assess changes in surfactant in various clinical situations. SP-A concentrations were standardized per milligram of albumin in the aspirate. The ratio of SP-A/albumin (µg/mg) in tracheal aspirates of 18 preterm infants with respiratory distress syndrome (RDS), in which samples were obtained within 12 hours of birth, was significantly lower (0.2 ± 0.1/µg/mg, mean ± S.D.) compared to a group of 20 non-RDS preterm infants of similar gestational age (15.8±7.4µg/mg) (p<0.05). None of the RDS infants had a SP-A/albumin ratio above l/µg/mg within 12 hours of birth, but the ratio exceeded 5µg/mg in all samples from non-RDS infants. The SP-A/albumin ratio significantly increased, however, at 48 to 72 hours after birth in infants with RDS (15.7 ± 9.5µg/mg). During the recovery phase of RDS, no difference was evident in the SP-A/albumin ratio in babies treated with artificial surfactant compared to those not treated .     

Novel, non-radioactive, simple and multiplex PCR-cRFLP methods for genotyping human SP-A and SP-D marker alleles

We have previously identified an allele of the human SP-A2 gene that occurs with greater frequency in an RDS population [12]. Because of the importance of SP-A in normal lung function and its newly emerging role in innate host defense and regulation of inflammatory processes, we wish to better characterize genotypes of both SP-A1 and SP-A2 genes. It has been determined that SP-D shares similar roles in immune response. Therefore, in this report we 1) describe a novel, non radioactive PCR based-cRFLP method for genotyping both SP-A and SP-D; 2) describe two previously unpublished biallelic polymorphisms within the SP-D gene; 3) present the partial sequence of one new SP-A1 allele (6A14) and describe other new SP-A1 and SP-A2 alleles; and 4) describe additional methodologies for SP-A genotype assessment. The ability to more accurately and efficiently genotype samples from individuals with various pulmonary diseases will facilitate population and family based association studies. Genetic polymorphisms may be identified that partially explain individual disease susceptibility and/or treatment effectiveness.     

Effect of some fractions of alveolar surfactant (phospholipids and SP-A) on the bactericidal activity of different antimicrobials against some respiratory pathogens

Objectives   To investigate the effects of physiologic concentrations, at alveolar level, of some fractions of pulmonary surfactant (phospholipids and SP-A) on the bactericidal activity of different antimicrobials against some respiratory pathogens.
Methods   The antimicrobial agents cefdinir, sparfloxacin, clarithromycin, teicoplanin, cefepime, ciprofloxacin, netilmicin and tobramycin, depending on their specific activity, were investigated against Staphylococcus aureus , Streptococcus pneumoniae , Haemophilus influenzae , Moraxella catarrhalis , Klebsiella pneumoniae and Pseudomonas aeruginosa . Killing curves were carried out with antimicrobials at 0.5 and 2 MIC, SP-A at 1 and 5 mg/L and phospholipids at 50 mg/L.
Results   Time-kill experiments showed that while SP-A never modified the activity of antimicrobials, phospholipids exerted, in some cases, a weak antagonistic effect. Among antibacterials and pathogens investigated, phospholipids were able to decrease the rate of killing of cefepime and ciprofloxacin only on P. aeruginosa , both at 0.5 and at 2 MIC, with an increase of about 1 log in CFU. The combination of SP-A and phospholipids never modified the effect observed in the presence of lipids alone.
Conclusions   The paucity of data only allow us to observe that the examined antibiotics do not have substantially reduced activity against respiratory pathogens studied in the presence of physiologic concentrations of some fractions of surfactant. Cefepime alone already exerted a small effect, and ciprofloxacin at 2 MIC, even in the presence of phospholipids, retained its bactericidal activity.     

急性肺损伤大鼠各组织SP-A含量变化及相关性研究

目的通过检测急性肺损伤（ALI）模型大鼠肺、大肠等组织及肺泡灌洗液（BALF）、血清肺表面活化蛋白A（SP-A）含量变化并分析其相关性,为中医＂肺与大肠相表里＂理论提供实验依据。方法采用脂多糖（LPS）气道内滴入制备急性肺损伤（ALI）大鼠模型,应用ELISA方法分别检测ALI及药物干预后ALI大鼠肺、大肠等组织及肺泡灌洗液（BALF）、血清SP-A含量变化,并进行相关性分析。结果随着急性肺损伤加重,ALI模型大鼠肺、大肠、BALF及血清SP-A含量逐渐降低,药物干预后能逆转这种趋势,呈一致性变化。且干预前后肺与大肠SP-A表达具有相关性（r=0.521,r=0.615,P〈0.01）。结论 SP-A在肺和大肠组织的含量变化相关性最密切。