Control of immunity and allergy by steroid hormones

Steroid hormones, especially glucocorticoids, androgens, and estrogens, have profound influence on immunity. Recent studies using cell-type specific steroid hormone receptor-deficient mice have revealed the precise roles of some of these hormones in the immune system. Glucocorticoids are known to have strong anti-inflammatory and immunosuppressive effects and pleiotropic effects on innate and adaptive immune responses. They suppress the production of inflammatory cytokines by macrophages and DCs and the production of IFN-γ by NK cells, thus inhibiting innate immunity. By contrast, glucocorticoids enhance the immune response by inducing the expression of IL-7R and CXCR4 in T cells and the accumulation of T cells in lymphoid organs in accordance with the diurnal change of the glucocorticoid concentration. Thus, glucocorticoids suppress innate immunity but enhance adaptive immunity. Androgens suppress the homeostasis and activation of ILC2s and the differentiation of Th2 and Th17 cells and enhance the suppressive function of Tregs, thereby alleviating allergic airway inflammation. Thus, these steroid hormones have pleiotropic functions in the immune system. Further investigations are awaited on the regulation of immunity and allergy by estrogens using cell-specific steroid hormone receptor-deficient mice.     

Tracheal intubation

Tracheal intubation is the act of placing a tube into the trachea. The tube enables oxygen delivery and removal of carbon dioxide, while also allowing for the administration of pharmacological agents. Intubation is the most reliable method of maintaining an airway under anaesthesia, and for protection against aspiration of stomach contents. Traditionally, intubation is achieved by direct visualization of the glottis, but now indirect laryngoscopy (via a videolaryngoscope) is a common alternative. Prior to embarking upon intubation, a thorough patient history and examination must be undertaken by the laryngoscopist; equipment must be prepared and checked; a trained assistant present; and an experienced anaesthetist available in case assistance is required. Once the endotracheal tube has been placed, correct positioning must be confirmed via both clinical examination and monitoring, including capnography. Tracheal intubation is a procedure that should only be undertaken by trained operators and is not without risk. It is important to note that it is failure to oxygenate patients rather than failure to intubate that ultimately leads to serious morbidity and mortality. The Difficult Airway Society has produced guidelines on how to manage unanticipated difficulty in tracheal intubation; it is essential that every practitioner trained to intubate patients is familiar with these algorithms and the key principles of safe airway management.     

肾盂输尿管连接部梗阻对对侧肾影响的实验研究

目的探讨肾盂输尿管连接部(UPJ)梗阻对对侧肾的影响。方法采用新西兰大白兔24只,随机分为完全梗阻组(组1)、部分梗阻组(组2)和假手术组(组3),每组8只。组1、2分别行右侧输尿管完全、部分结扎,组3只显露而不结扎输尿管。术后4周处死,切除对侧肾。处死前尿路造影示组1、2兔均发生右侧肾积水。应用电子天平测定对侧肾实质重量,采用FITC-Annexin-V/PI双染色流式细胞仪检测对侧肾皮髓质细胞凋亡率。所有标本均行病理学检查。结果4周后,组1、2、3对侧肾实质重量分别为(3.96±0.20)、(3.47±0.19)、(3.20±0.21)g/kg体重,组1、2与组3比较差异均有统计学意义(P<0.05);对侧肾皮质的细胞凋亡率分别为(2.19±0.83)%、(2.17±0.79)%和(2.14±0.76)%,组间两两比较差异均无统计学意义(P>0.05);对侧肾髓质的细胞凋亡率分别为(23.75±2.34)%、(11.82±1.40)%和(2.36±0.65)%,组间两两比较差异均有统计学意义(P<0.01)。UPJ梗阻4周后,组2对侧肾间质充血、轻度水肿,部分肾小管扩张,管腔内存在坏死脱落的物质;组1对侧肾改变更为明显。结论UPJ梗阻不仅引起对侧肾实质代偿性增生,同时还造成对侧肾损害。     

Relationship Between Exhaled Carbon Monoxide and Airway Hyperresponsiveness in Asthmatic Patients

The study objectives were to analyze the changes in exhaled carbon monoxide (COex) induced by histamine provocation challenge in asthmatic patients and to evaluate the relationship between COex and airway sensitivity and reactivity. Levels of COex were measured in 105 nonsmoking mildly asthmatic subjects before and after histamine provocation challenge. Dose-response curves were characterized by their sensitivity (PD₂₀) and reactivity. Dose-response slope (DRS), continuous index of responsiveness (CIR), and bronchial reactivity index (BRI) were determined as reactivity indices. Bronchial challenge was positive for 47 subjects and negative for 58. The COex levels rose significantly after bronchial challenge in the positive response group (4.49 ± 0.4 vs. 5.74 ± 0.57 ppm, p = 0.025) and in the negative response group (2.84 ± 0.25 vs 4.00 ± 0.41 ppm, p = 0.000). An inverse relation between basal COex and PD₂₀ was found (r = - 0.318, p = 0.030). In all subjects, a proportional direct relationship between COex and DRS (r = 0.214, p = 0.015), CIR (r = 0.401, p = 0.000), and BRI (r = 0.208, p = 0.012) was observed. On stepwise multiple linear regression analysis, COex only significantly correlated with CIR (multiple r² = 0.174, p = 0.000). In conclusion, exhaled CO determination is a noninvasive inflammatory marker of the respiratory tract, which shows an acceptable association with airway hyperresponsiveness.     

Subakute Verlegung der Atemwege infolge eines retropharyngealen H?matoms nach Halstrauma

Mechanical airway obstruction secondary to retropharyngeal bleeding is rare. In most cases such a complication is described after head and neck trauma. Complicating factors include anticoagulant therapy, tumour, aneurysm, infection or major cervical spine injury. A precise initial diagnosis is necessary to avoid a life-threatening situation. Lateral X-ray and computed tomography is essential for safe management. Treatment depends upon size of the haematoma as well as the clinical course of the patient. Smaller haematomas may be observed. Lager haematomas and those that fail to reabsorb should undergo drainage.      

3种钾通道在哮喘豚鼠气道高反应中的作用

目的：探讨钙激活钾通道（KCa）、延迟整流型钾通道（Kdr）和ATP敏感型钾通道（KATP）在哮喘豚鼠气道高反应中的作用。 方法： 采用离体气管环张力实验，观察加入特异性钾通道阻断剂后，与不加阻断剂相比气管环对组胺反应的量效曲线的差异。 结果： （１）加入KCa阻断剂TEA后，对照组气管环对组胺的反应变化不显著，而哮喘组气管环对10-4mol/L、10-3mol/L组胺的收缩反应均显著低于不加TEA的气管环(P<0.01)，量效曲线明显下移；（2）加入Kdr阻断剂4-AP后，对照组气管环对10-3mol/L组胺的最大收缩反应明显下降(P<0.05)，组胺的量效曲线下移，哮喘组气管环对10-4mol/L、10-3mol/L组胺的收缩反应均低于不加4-AP的气管环(P<0.01)，且下降程度较对照组大（P<0.05），量效曲线明显下移；（3）加入KATP阻断剂glibenclamide后，对照组和哮喘组气管环对组胺的量效曲线与不加glibenclamide的气管环相比变化均无明显差异。 结论： 在豚鼠哮喘模型中，KCa和Kdr活性的降低在气道高反应的发生中起介导作用，KATP作用不明显。     

两种不同方法测定低水平压力支持通气时气道阻断压与自主呼吸时常规方法测定值的相关性分析

目的 拟比较以两种不同方法测定低水平压力支持通气（pressure support ventilation，PSV）病人的气道阻断压（P0．1）与自主呼吸时常规方法测定值的相关性。方法 12例机械通气病人，断开呼吸机自主呼吸时以常规方法测定P0．1得到P0．1-SB：在PSV水平为5cmH20，以常规方法和按压呼气末暂停键测定P0．1分别得到P0．1-PSV5和P0．1-PSV5eeo．分析后二者与前者之间的相关性。结果 P0．1-SB与P0．1-PSV5之间差异无显著性，P0．1-PSV5ee0分别小于P0．1-SB与P0．1-PSV5，差异有显著性；P0．1-PSV5eeo与P0．1-PSV5和P0．1-SB之间的相关系数均为0．97。结论 按压呼气末暂停键测定PSV水平为5cmH2O的P0．1值与常规方法测定的PSV水平为5cmH2O以及自主呼吸时的测定值相比，其值偏小,但前者与后二者之间具有良好的相关性。     

血清磷、肌酸激酶及其同工酶的测定在肠梗阻诊断中的应用

肠梗阻是临床常见的急腹症，绞窄性肠梗阻的死亡率可高达４５％～３０％，我们自１９９５年８月至１９９７年４月共收治肠梗阻５３例，其中单纯性肠梗阻２８例，经手术证实为绞窄性肠梗阻２５例（其中肠坏死８例），在治疗前均测定血清磷、肌酸激酶及其同工酶，其结果：本组病例中血清磷升高者１４例，其中以８例肠坏死为显著，肌酸激酶及其同功酶的升高也以绞窄性肠梗阻为明显，其中又以发病时间在４８小时以内者和８例肠坏死者为著，因此，我们认为：血清磷、肌酸激酶及其同工酶的测定可以作为判断肠管是否发生绞窄及坏死的辅助诊断指标