Narrowly Distributed Surfactant‐Free Polystyrene Latex with a Water‐Soluble Comonomer

Summary: The surfactant‐free synthesis of latex polymers of styrene and sodium styrenesulfonate (NaSS) was investigated. The development of size and size distribution of the particles was studied by photo‐correlation spectroscopy (PCS) and transmission electronic microscopy (TEM). The effects of NaSS concentration and the order of addition of reactants were examined in detail. The results showed that the particle size decreases with an increase in the styrene sulfonate concentration. The polydispersity index can be reduced by mixing NaSS with styrene homogeneously before adding initiator, but this leads to a slightly larger mean particle size.

TEM image of surfactant‐free polystyrene latex made by the modified method.     

Polyfunctional role of the alveolar brush cells in the rat lung

An investigation by scanning and transmission electron microscopy revealed an increase in the number of vacuoles in the apical part of the cytoplasm in the alveolar brush cells of the regenerating rat lung, hyperplasia of the lamellar complex, and activation of the protein-synthesizing apparatus. Immature surfactant material and secretory granules with an osmiophilic center were found in the cytoplasm of the brush cells. Colchicine, injected intramuscularly into rats six times in the course of the 24 h before sacrifice in a dose of 0.1 mg/100 g body weight, affected neither the number, topography, nor the structure of the bundles of microfibrils present in large numbers in the brush cells. Meanwhile, under the influence of colchicine, some of the microvilli of the alveolar brush cells undergo destruction and resorption. These data on the ultrastructural organization of these cells indicate that they can perform several functions: absorptive, contractile, and secretory.Department of Geographic Pathology, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 10, pp. 485–489, October, 1979.     

机械通气下应用肺表面活性物质治疗新生儿肺炎合并呼吸衰竭的疗效

目的：探讨新生儿肺炎合并呼吸衰竭治疗中机械通气下应用肺表面活性物质的疗效。方法：回顾性选取2017年2月至2022年2月无锡市儿童医院新生儿科收治的新生儿肺炎合并呼吸衰竭患儿80例,依据治疗方法分为机械通气下应用肺表面活性物质治疗组(观察组)、机械通气治疗组(对照组)两组,各40例。分析两组患儿血气指标、平均动脉压(MAP)和呼吸力学指标、机械通气时间、总吸氧时间、住院时间、并发症发生情况之间的差异。结果：治疗前,两组患儿的动脉血氧分压(PaO₂)、氧合指数(PaO₂/FiO₂)、动脉血二氧化碳分压(PaCO₂)、氢离子浓度指数(pH)、MAP、呼气末正压(PEEP)、平台压(Pplat)、气道峰压(PIP)之间比较,差异均无统计学意义(P> 0.05);治疗后,两组患儿的PaO₂、PaO₂/FiO₂均高于治疗前,PaCO₂、MAP、PEEP均低于治疗前,差异均具有统计学意义(P <0.05),但治疗...     

无创高频振荡通气在极低出生体重早产儿呼吸窘迫综合征初始呼吸支持治疗中的应用

目的探讨经鼻无创高频振荡通气(NHFOV),在呼吸窘迫综合征(RDS)极低出生体重早产儿初始呼吸支持治疗的临床疗效。 方法选择2018年2月至2020年4月,于徐州市中心医院新生儿重症监护病房(NICU)治疗的92例RDS极低出生体重早产儿为研究对象。采用随机数字表法,将其分为NHFOV组(n＝48,采取NHFOV治疗)及经鼻持续气道正压通气(NCPAP)组(n＝44,采取NCPAP治疗)。对2组RDS极低出生体重早产儿一般临床资料,无创通气治疗前、后动脉血气分析指标,疗效,呼吸支持治疗相关并发症发生率及患儿死亡率,采用成组t检验、χ²检验及Mann-Whitney U检验进行统计学比较。本研究经徐州市中心医院医学伦理委员会审核批准(审批文号：XZXY-LJ-20170328-006),并且与患儿监护人均签署临床研究知情同意书。 结果①一般临床资料比较：2组RDS极低出生体重早产儿的性别、出生胎龄与体重及生后1、5 min Apgar评分,入院日龄及分娩前24 h母亲糖皮质激素使用率等一般临床资料比较,差异均无统计学意义(P>0.05)。② 2组RDS极低出生体重早产儿动脉血气分析指标组间比较：NHFOV组RDS极低出生体重早产儿无创通气治疗后1 h、24 h动脉血二氧化碳分压(PaCO₂)分别为(45.8±6.5) mmHg(1 mmHg＝0.133 kPa)及(40.8±4.7) mmHg,均显著低于NCPAP组的(49.3±5.7) mmHg及(44.2±5.2) mmHg;治疗后1 h、24 h动脉血氧分压(PaO₂)与吸入氧浓度分数(FiO₂)比值(P/F)分别为(198.8±30.5) mmHg及(215.1±32.1) mmHg,均显著高于NCPAP组的(176.4±28.1) mmHg及(190.0±29.7) mmHg,并且上述差异均有统计学意义(t＝2.809、3.301、3.663、3.881,P＝0.003、<0.001、<0.001、<0.001)。③2组动脉血气分析指标分别进行组内比较均为：无创通气治疗后24 h的pH值及治疗后1、24 h的PaCO₂水平,均较治疗前改善,而且治疗后24 h的P/F值高于治疗后1 h,并且差异均有统计学意义(P<0.05)。④无创通气疗效比较：NHFOV组RDS极低出生体重早产儿无创通气治疗后,肺表面活性剂(PS)使用率及有创机械通气率(22.9%、6.3%),均显著低于NCPAP组(45.5%、20.5%),并且差异均有统计学意义(χ²＝5.219、4.084,P＝0.022、0.043)。2组RDS极低出生体重早产儿无创通气时间、柠檬酸咖啡因使用率、频繁呼吸暂停发生率及总用氧时间比较,差异均无统计学意义(P>0.05)。⑤2组RDS极低出生体重早产儿鼻损伤、肺气漏、新生儿坏死性小肠结肠炎(NEC)、Ⅲ~Ⅳ级脑室内出血(IVH)、早产儿视网膜病(ROP)(≥Ⅱ期)及支气管肺发育不良(BPD)发生率,以及患儿死亡率比较,差异均无统计学意义(P>0.05)。 结论与NCPAP比较,NHFOV用于RDS极低出生体重早产儿初始呼吸支持治疗,能改善氧合、减少二氧化碳(CO₂)潴留、减少有创机械通气及PS使用,同时不增加呼吸支持治疗相关并发症发生。     

Effect of Locus Coeruleus Stimulation on Ocular Hypertension and Pathology of Pulmonary Surfactant during Chronic Emotional Stress

In chronic experiments on rabbits and rats, parameters of eye homeostasis (intraocular pressure and ocular hydrodynamics) and lungs (water balance and surface-active properties of surfactant) were studied during electrical stimulation of the locus coeruleus against the background of chronic stress induced in rabbits by repeated electrical stimulation of the ventromedial nucleus and in rats by daily immobilization on a platform. Stimulation of the locus coeruleus eliminated ocular hypertension of hypothalamic origin and stress-induced disturbances in surface activity, blood volume, and water balance in the lungs.     

The Effects of Permeation Enhancers on the Surface Morphology of the Rat Nasal Mucosa: A Scanning Electron Microscopy Study

A rat model has been developed to compare relative morphological changes in the nasal mucosa after exposure to potential membrane permeation enhancers. Scanning electron microscopy was used to characterize gross structural and specific cellular changes following exposure. Micrographs of the rat nasal mucosa were scored in four categories: (1) mucosal surface integrity, (2) ciliary morphology, (3) mucus/extracellular debris, and (4) presence of red blood cells. The order of increasing morphological damage resulting from a 5-min exposure to each surfactant was 0.5% Solulan C-24 0.5% Solulan C-24/0.5% sodium tauro-24,25-dihydrofusidate (STDHF) < 0.5% STDHF < 1.0% STDHF 1.0% Laureth-9 < 1.0% sodium taurodeoxycholate 1.0% sodium deoxycholate. The changes observed in the mucosal morphology after exposure to the various surfactants are in general agreement with data in the literature. This model is able to compare rapidly the relative morphological effects on the mucosal membrane of different nasal formulations.     

Study on Pulmonary Surfactant of Sudden Death of Infant

Objective To find the pathogenesis of sudden infant death syndrome (S IDS) from changes of pulmonurry surfactant. Methods By means of thin-layer ckromatography technique, surfactant in whole lung specimens of 10 infants with SIDS and 10 control infants without SIDS (dead of nonrespiratory diseases ) were examined qualitatively and quantitatively. Results Eleven components in pulmonary surfactant were examined qualitatively, including lysophosphatidylcholine , sphingomyelin , phosphatidylcholine , phosphatidylserine , phosphatidylinositol , phos phatidylethanolamine , phosphatidylglycerol , diphosphatidylylycerol , phosphatidic acid, cholesterol and neutral lipids. Quantitative examination showed that the amount of surfactant of whole lung specimens in sudden death group [-(8.9±1.0) rng/g wet lung weight] was significantly less than that in control group [-(12. 6±1.4) mg/g uet lung weight, P＜0. 01]. Qualitative variance showed that the percentages of phosphatidylcholine (49. 4 % ± 2. 0 % ) and phosphatidylylycerol ( 2. 6 % ± 0. 7 % ) decreased markedly in sudden death group compared with those in control group (61.5 % ± 3. 0 % and 4.3 % ±1. 5%, P ＜ 0. 01 ). Conclusion Before death there is serions defect on metabolism of pulmonary surfactant in sudden death infants, with the amount decreasing and the ratio of its components being disturbed, which is one of the important pathogenies of SIDS.     

Evaluating the hazard of dodecyl alkyl sulphate to natural ecosystems using indigenous protistan communities

The effect of the surfactant dodecyl alkyl sulphate (C12AS) on the structure and function of lotic protistan assemblages was examined using the Experimental Stream Facility (ESF) operated by the Procter and Gamble Company. Population- and community-level responses to C12AS were monitored on introduced substrates placed in the channels 28 days prior to dosing (mature communities) as well as those placed in the channels on day 0 of dosing (immature communities), to allow for a broad assessment of the effect of the chemical on processes contributing both to community development and maintenance. C12AS appeared to elicit a subsidy response from the native protistan assemblage which may have resulted from both positive and negative responses at trophic levels above and below the assemblage. Protistan responses to the surfactant tended to occur more rapidly and be more sensitive than those documented for invertebrates and fish. C12AS elicited a modest response (i.e. a 20% change) from several reliable parameters including community respiration (reduced dissolved oxygen at 289 g per L), protozoan species richness (increased at 63 g per L) and protozoan community composition (increased dissimilarity at 1254 g per L). Responses to C12AS exceeded expected exposures in the real world by a factor of six or greater thereby indicating that the hazard of exposure to C12AS to stream communities is low. The results of this study support the use of mesocosms as decisive tools for evaluating the hazard posed by consumer product chemicals to natural communities and ecosystems     

正丁基葡萄糖苷合成的反应机理与动力学

在最佳反应条件下,采用直接法由葡萄糖与正丁醇反应合成正丁基葡萄糖苷,研究了该反应的反应机理,提出了直接法合成正丁基葡萄糖苷的宏观动力学模型,该过程为表观假一级可逆反应。     

新生儿呼吸窘迫综合征肺表面活性物质治疗后肺氧合功能和尿量变化的观察

目的　探讨新生儿呼吸窘迫综合征 (RDS)予肺表面活性物质 (PS)治疗后的尿量变化及尿量与肺氧合功能的关系。方法　对新生儿重症监护病房 (NICU)行呼吸机治疗的 2 0例RDS患儿予血气监测及每小时尿量和入量监测。结果　观察组 (PS组 )最大尿量峰值出现于生后 6 0h ,与对照组比较有显著性差异 (P <0 0 5 )。尿量 /入量比值PS组于生后 48h即大于 0 8,而对照组的上述比值大于 0 8出现于生后 6 0h。尿量与动脉 /肺泡氧分压比值 (PaO2 /PAO2 )有显著相关性 (r =0 7414,P <0 0 5 )。结论　RDS病程中随着尿量增加肺氧合功能改善 ,予PS治疗后利尿期最大尿量峰值增大 ,出现时间早 ,提示在PS治疗后更应该密切观察尿量变化 ,判断病情的恢复。