Identification of Bordetella pertussis virulence-associated outer membrane proteins

Bordetella pertussis virulence-associated 30-, 32-, 90- and 95-kDa outer membrane proteins were purified and their N-terminal amino acid sequences were determined. The 30- and 32-kDa outer membrane proteins showed identity to the C-terminal region of the precursors of the serum resistance protein (BrkA) and the tracheal colonization factor, respectively. We confirmed the cleavage site of these precursors after N731 for BrkA and after N393 for tracheal colonization factor. Associated with the 32-kDa outer membrane protein, we found a new group of 36-kDa virulence-associated peptides. The 95-kDa outer membrane protein showed identity to Vag8. The 90-kDa outer membrane protein did not show homology with the described proteins. We report the N-termini sequence of Vir-90, a novel potential virulence factor.     

EGF signalling regulates cell invagination as well as cell migration during formation of tracheal system in Drosophila

 The Drosophila tracheal system is a network of epithelial tubes that arises from the tracheal placodes, lateral clusters of ectodermal cells in ten embryonic segments. The cells of each cluster invaginate and subsequent formation of the tracheal tree occurs by cell migration and fusion of tracheal branches, without cell division. The combined action of the Decapentaplegic (Dpp), Epidermal growth factor (EGF) and breathless/branchless pathways are thought to be responsible for the pattern of tracheal branches. We ask how these transduction pathways regulate cell migration and we analyse the consequences on cell behaviour of the Dpp and EGF pathways. We find that rhomboid (rho) mutant embryos display defects not only in tracheal cell migration but also in tracheal cell invagination unveiling a new role for EGF signalling in the formation of the tracheal system. These results indicate that the transduction pathways that control tracheal cell migration are active in different steps of tracheal formation, beginning at invagination. We discuss how the consecutive steps of tracheal morphogenesis might affect the final branching pattern. Received: 9 October 1998 / Accepted: 5 November 1998     

AECOPD并重度呼吸衰竭患者有创机械通气的治疗时机探讨及其预后的影响因素分析

摘要 目的：探讨慢性阻塞性肺疾病急性加重（AECOPD）合并重度呼吸衰竭患者有创机械通气的治疗时机,并分析其预后的影响因素。方法：选取2020年3月~2021年12月期间于首都医科大学附属北京世纪坛医院治疗的161例AECOPD合并重度呼吸衰竭患者,按照气管插管时间分为早期组（n=89）和延期组（n=72）,对比两组治疗后临床指标、血气分析指标及28 d内病死率（预后）。根据预后的不同将患者分为死亡组（n=29）和存活组（n=132）,收集患者的一般资料和实验室资料,采用Logistic回归分析预后的影响因素。结果：早期组的总机械通气时间、有创通气时间、重症监护室（ICU）住院时间均短于延期组（P<0.05）。两组治疗后动脉血二氧化碳分压（PaCO₂）较治疗前下降,氧合指数（OI）、动脉血氧分压（PaO₂）较治疗前升高,且早期组变化程度大于延期组（P<0.05）。延期组28 d内病死率为15/72（20.83%）。早期组28 d内病死率为14/89（15.73%）,两组患者的28 d病死率对比无差异（P>0.05）。单因素分析结果显示,AECOPD合并重度呼吸衰竭患者的预后影响因素与并发呼吸机相关肺炎、并发多脏器功能不全综合征、年龄、PaCO₂、血红蛋白（Hb）、血尿素氮（BUN）、白细胞计数（WBC）、pH值、中性粒细胞计数/淋巴细胞计数比值（NLR）、血小板计数/淋巴细胞计数（PLR）、C反应蛋白（CRP）、D-二聚体（D-D）、B型尿钠肽有关（P<0.05）。AECOPD合并重度呼吸衰竭患者预后不良的危险因素主要有并发呼吸机相关肺炎、并发多脏器功能不全综合征、PaCO₂偏高、年龄偏大、Hb偏低、pH值偏低、D-D偏高（P<0.05）。结论：AECOPD合并重度呼吸衰竭患者早期使用有创机械通气,可有效改善血气分析,缩短有创通气时间、总机械通气时间、ICU住院时间。并发呼吸机相关肺炎、并发多脏器功能不全综合征、PaCO₂偏高、年龄偏大、Hb偏低、pH值偏低、D-D偏高均是导致AECOPD合并重度呼吸衰竭患者预后不良的危险因素。     

使用机械通气联合限制性液体复苏对重度颅脑损伤患者的急救效果及对远期认知功能影响

摘要 目的：探讨使用机械通气联合限制性液体复苏对重度颅脑损伤患者的急救效果及对远期认知功能影响。方法：选取我院2020年1月到2022年12月急诊收治的90例重度颅脑损伤患者作为研究对象,应用随机数字表法将所有患者分为观察组与对照组,每组45例。所有患者均采取常规重型颅脑损伤治疗,对照组患者在损伤后立即给予机械通气,并采取常规液体复苏措施进行治疗。观察组在损伤后立即给予机械通气,并采取限制性液体复苏治疗,对比两组患者急救效果,急救治疗前与急救治疗后1 h的血气指标变化情况,急救治疗前与急救治疗后1 d的血尿素氮（BUN）、血清肌酐（Scr）、乳酸、肌酸激酶（CK）相关生化指标表达水平,最后分别在患者苏醒时、术后3 d、6 d、10 d检测两组患者S100B蛋白与褪黑素表达水平。结果：观察组患者苏醒时间、说话时间、总输液量以及死亡率明显低于对照组,观察组GOS评分明显高于对照组（P＜0.05）;治疗前两组患者血氧饱和度（SpO₂）、动脉血二氧化碳分压（PaCO₂）水平对比无明显差异（P＞0.05）,治疗后,对照组SpO₂水平降低,观察组无明显变化,两组患者PaCO₂水平均降低,且观察组低于对照组（P＜0.05）;治疗前两组患者BUN、Scr、乳酸、CK相关指标表达水平对比无明显差异（P＞0.05）,治疗后对照组患者CK水平升高,观察组无明显变化,且观察组明显低于对照组,BUN、Scr、乳酸水平均降低,且观察组明显低于对照组（P＜0.05）;两组患者苏醒时S100B 蛋白、褪黑素对比无明显差异（P＞0.05）,术后3 d、6 d、10 d S100B 蛋白明显降低,且观察组低于对照组,术后3 d、6 d、10 d褪黑素明显升高,观察组高于对照组（P＜0.05）。结论：使用机械通气联合限制性液体复苏能够提升重度颅脑损伤患者的急救效果,降低患者死亡率,且能够及时改善患者血氧饱和度、动脉血二氧化碳分压相关血气指标水平,减轻对患者心功能、肾功能带来的损伤,同时能够降低对患者神经功能产生的损伤情况。     

针刺疗法联合穴位贴敷对急性呼吸衰竭机械通气患者血气分析指标、膈肌功能及炎症免疫指标的影响

摘要 目的：观察穴位贴敷、针刺疗法联合治疗对急性呼吸衰竭机械通气患者血气分析指标、膈肌功能及炎症免疫指标的影响。方法：选择2021年11月～2022年12月期间在安徽中医药大学附属六安医院接受治疗的92例急性呼吸衰竭机械通气患者,按照随机数字表法将患者分为对照组（常规治疗,46例）和研究组（对照组的基础上增加针刺疗法联合穴位贴敷治疗,46例）。对比两组血气分析指标、膈肌功能、炎症免疫指标及胃肠功能,同时记录两组并发症发生率。结果：研究组撤机前氧合指数（OI）、pH、动脉血氧分压（PaO2）高于对照组,动脉血二氧化碳分压（PaCO₂）低于对照组（P<0.05）。研究组撤机前右侧膈肌呼气末厚度（Tdi-ee）、吸气末厚度（Tdi-ei）、膈肌增厚分数（TFdi）低于对照组（P<0.05）。研究组撤机前超敏C反应蛋白（hs-CRP）、降钙素原（PCT）、白细胞计数（WBC）低于对照组,CD4⁺高于对照组（P<0.05）。研究组撤机前胃肠功能评分低于对照组（P<0.05）。两组并发症发生率组间对比无统计学差异（P>0.05）。结论：针刺疗法联合穴位贴敷在改善急性呼吸衰竭机械通气患者的血气分析指标、膈肌功能、炎症免疫指标中的应用价值较好。     

高频双向喷射通气对麻醉犬的二氧化碳排除效能及其影响因素

观察了高频双向喷射通气(HFTJV)时反喷驱动压和通气频率对麻醉犬CO_2排除效能的影响以及潮气量(V_T)的变化特点。结果表明:在通气频率、正喷驱动压及吸/呼比均相同时,HFTJV时的Paco_2,V_T及FRC较高频喷射通气(HFJV)时均显著降低(P<0.05),Vco_2及pH均显著升高(P<0.01),而Pao_2和气道压则无明显改变。当HFTJV的反喷驱动压从2.06,4.31增加到6.57kPa/kg时,Paco_2,Vco_2,Pao_2,V_T及FRC等均无明显改变。无论在HFJV或HFTJV时,当通气频率从60,100增加到200次/min时,Paco_2均随之升高,并与V_T呈显著负相关。结果提示,HFTJV较HFJV具有更强的CO_2排除作用,HFTJV时的CO_2排除主要受潮气量的影响。     

The effect of ventilation rate on proliferation and hyperhydricity of Dianthus caryophyllus L

Summary Comparative studies of carnation micropropagation under four different ventilation rates showed that using gas-permeable filters, with gelled or liquid media and modifying the volume of culture medium, it was possible to establish a suitable hydric state to obtain good proliferation rates with gelled and liquid medium, as well as optimal acclimatization of microcuttings. The following parameters were measured: ventilation rate, gas exchange coefficients, relative water loss, increase of agar concentration, micropropagation rates, percentage of hyperhydricity, and acclimatization rates. Our results confirm that it is possible to avoid hyperhydric plants cultured in liquid medium with the use of ventilated culture vessels through the control of the water relations during the multiplication phase and, at the same time, keeping the micropropagation rate.     

Change in the peripheral CO2 chemoreflex from rest to exercise

A single-breath CO₂ test of peripheral chemosensitivity has recently been described, and elaborated based on model simulations. This study was designed to measure the peripheral CO₂ chemoreflex at rest and during heavy exercise to see if carotid chemosensitivity to CO₂ increased. Ten healthy, adult males performed an incremental exercise test to determine their ventilatory anaerobic threshold (VAT), and 20 minutes of steady-state exercise at a pre-determined power output above VAT. Arterialized venous blood was obtained during each minute of incremental exercise to verify development of metabolic acidosis. Carotid chemosensitivity was tested repeatedly at rest and in steady-state exercise by the ventilatory response to a single breath of 13% CO₂ in air. The peripheral chemoreflex for CO₂ for the group of subjects doubled from rest to exercise (mean 0.0961 · s^–1 · kPa^–1) with all subjects showing an increase. We conclude that the gain of the carotid CO₂ chemoreflex increases from rest to exercise at work above the VAT.     

Rhythms of passive and active ventilation, and circulation recorded in diapausing pupae of Mamestra brassicae using constant volume respirometry

Abstract.  The periodically occurring convective inflow of air into the tracheal system, or passive suction ventilation, together with the cyclic bursts of release of CO₂ and active ventilation, is recorded in diapausing pupae of Mamestra brassicae . A constant volume respirometer combined with an opto-cardiograph-actograph is used. In all pupae with a metabolic rate of 0.025–0.054 mL g⁻¹ h⁻¹, the bouts of almost imperceptible abdominal contractions are recorded during the bursts of carbon dioxide release and this mode of active ventilation is qualified as extracardiac haemocoelic pulsations. The pupae whose metabolic rate is 0.052–0.075 mL⁻¹ g⁻¹ h⁻¹ show more vigorous abdominal contractions. The results demonstrate that, in diapausing pupae, characterized with low metabolic rates, both passive suction ventilation, referred to also as passive suction inspiration, and active ventilation occurs. In approximately 50% of the pupae, each gas exchange microcycle during the interburst periods begins with a miniature PSI followed by a microburst of CO₂ release; in approximately 30% of the individuals, passive suction inspirations occur separately from CO₂ microbursts; in the remaining pupae, miniature ones without microbursts of CO₂ are recorded. A typical event is heartbeat reversion: in longer periods, the heart peristalses are directed forward (anterograde of heartbeat) and, in shorter periods, the heart peristalses are directed backward (retrograde of heartbeat). At 0 °C, the cyclic release of CO₂ and miniature passive suction inspirations during the interburst periods are preserved at lower frequencies but active ventilation is lost.     

Monitoring of gas exchange cycles and ventilatory movements in the pine weevil Hylobius abietis: respiratory failures evoked by a botanical insecticide

The large pine weevil, Hylobius abietis (L.) (Coleoptera: Curculionidae), is the most important insect pest of young coniferous plants. The implementation of new control methods requires not only a profound knowledge of the ecology and behaviour of the pest, but particularly of its physiology. Standard metabolic rate (SMR) and discontinuous gas exchange cycles (DGCs) were recorded in parallel with abdominal ventilation movements in adults of H. abietis using a differential electrolytic respirometer‐actograph. Quiescent weevils displayed DGCs of the constriction, flutter, and ventilation phases of the CFV type, while bursts of carbon dioxide were always accompanied by abdominal pumping movements, i.e., muscular ventilation in the closed subelytral cavity (SEC). In some beetles the C phase was absent and thus (C)FV cycles were recorded. In addition, at the beginning and often at the end of a burst, the SEC was rhythmically opened and closed by movements of the last abdominal segments. Continuous pumping movements and an absence of DGCs were signs of stress imposed by handling or by a new environment, even if the beetle was not moving. All individuals showed clear DGCs after recovering from handling and apparatus stress lasting 2–3 h. The results show that in the monitoring of DGCs, it is essential to determine whether they are of the constriction, flutter, and open phases (CFO), or the CFV subtype of the constriction, flutter, and burst (CFB) cycles. Use of our simple closed‐system respirometer enables non‐invasive simultaneous recording of SMR, oxygen uptake, DGCs, and active ventilation in H. abietis and other beetles. The topical application of adult H. abietis with sublethal doses of a botanical insecticide, NeemAzal T/S, caused essential respiratory failures: cyclic gas exchange was lost and irregular pumping movements appeared. In the treated beetles normal DGCs did not resume.