Aberrant right subclavian artery as a new cardiac sign in second- and third-trimester fetuses with Down syndrome

OBJECTIVE: The right subclavian artery arises normally as the first vessel from the brachiocephalic artery of the aortic arch. An aberrant right subclavian artery arises as a separate vessel from the aortic isthmus and crosses to the right, behind the trachea. This variant is present in <1% of the normal population; however, in subjects with Down syndrome, an incidence between 19% and 36% was reported. The purpose of this study was to assess the possibility of the detection of an aberrant right subclavian artery in fetuses with Down syndrome. STUDY DESIGN: Fourteen consecutive fetuses with prenatally detected Down syndrome were examined between 18 and 33 weeks of gestation. The presence of an aberrant right subclavian artery was determined by visualization of the transverse 3-vessel trachea view of the upper thorax with color Doppler ultrasonography. RESULTS: The right subclavian artery was visualized in 100% of fetuses (14/14) with Down syndrome. An aberrant right subclavian artery was identified in 35.7% of trisomy 21 fetuses (5/14). In 1 fetus, the aberrant right subclavian artery was the only abnormal ultrasound finding. In 3 fetuses, an aberrant right subclavian artery was associated with an intracardiac echogenic focus plus additional extracardiac markers. In the fourth fetus, an aberrant right subclavian artery was associated with an atrioventricular septal defect. All 9 fetuses with Down syndrome with a normal origin of the right subclavian artery had additional cardiac and/or extracardiac abnormalities. In 12 cases, pregnancy was terminated; 2 fetuses were live born. CONCLUSION: This preliminary study suggests that the in utero identification of an aberrant right subclavian artery may be a new ultrasound marker to be found in fetuses with Down syndrome. Further studies are required to assess the incidence of aberrant right subclavian artery in normal fetuses.     

Successful management of concommitant blunt injury to the trachea, esophagus, and cervical spine in a 6-year-old girl

A 6-year-old girl sustained an unusual constellation of injuries after blunt trauma sustained in a motor vehicle accident. Transection of the trachea and esophagus were managed successfully by repair through a median sternotomy while the patient was on cardiopulmonary bypass. A cervical spinal injury was fixated with halo traction and a femur fracture with internal fixation.     

Tracheal mucormycosis presented as an intraluminal soft tissue mass

BACKGROUND: Mucormycosis is a potentially lethal disease caused by an opportunistic fungal infection. It occurs mostly in diabetic or immunosuppressed patients and usually involves the lungs or paranasal sinuses. METHODS: We report a rare case of a patient with diabetic ketoacidosis who presented with progressive cough and dyspnea. CT of the neck and chest showed an intraluminal soft-tissue mass extending from the first tracheal ring to the thoracic inlet, causing severe destruction of the trachea. Direct laryngoscopy and biopsy demonstrated hyphal invasion with architecture typical of invasive mucormycosis. RESULTS: The patient underwent resection of the upper trachea and prolonged amphotericin B therapy and is disease free at 24 months after surgery. CONCLUSIONS: In patients with diabetes presenting with progressive hoarseness, dyspnea, and endobronchial mass, a fungal infection should be considered. In case of invasive tracheal mucormycosis, prompt diagnosis and early surgical resection may help improve survival.     

Is the Trachea a Marker of the Type of Environmental Pollution?

OBJECTIVES/HYPOTHESIS: The differentiated character of changes in the mucous relief of the trachea as induced by air containing pollutants from the wastes of nickel-, mercury-, and cement-producing plants and by Candida albicans occurring in the waste disposal site of a large town are identified. The trachea was chosen because it is the entrance gate for the penetration of polluted air into the lungs. Changes on the trachea influence the character and extent of changes in lungs. STUDY DESIGN: Histological study with Viennese grey strain laboratory rabbits and rats caught directly on an investigated site. METHODS: We present new results of the functional morphology of the respiratory system as the results of scanning and transmission electron microscopy studies that can reveal character and range of damage of mucosal relief of trachea relevant to the functional dynamics of mucociliary clearance. Under physiological conditions this mechanism allows that only respirable dust particles enter the deep respiratory tract. RESULTS: In case of a damaged tracheal relief because of exposure to various aerosols, the functional morphology is changed, which aids in understanding the mechanisms damaging to mucociliary clearance induced by living in heavily polluted areas. CONCLUSION: Understanding of these morphological changes on base of detailed electron microscopic findings sheds new light on elaborating novel diagnostic methods for clinical practice.     

The effect of chronic ethanol administration on nitric oxide-mediated responses in rat isolated trachea preparation

1. In the present study, we investigated the effect of chronic ethanol administration on nitric oxide (NO)-mediated responses in rat isolated trachea preparation. 2. Ethanol was given to rats in a modified liquid diet for 21 days. Isolated tracheal rings were then used to obtain responses to electrical field stimulation (EFS) after precontraction with 100 microM histamine. The parameters of field stimulation were as follows: supramaximal voltage of 50 V, 0.5 ms duration, 10-s train; 0.5, 1, 3, 5, 10, 20, 30 and 50 Hz at 2-min intervals. The effects of L-and D-arginine (10(-6) M) on the responses to field stimulation (10-20 Hz) were studied. In other experiments, we tested the effects of N(omega)-nitro-L-arginine methyl ester (L-NAME, 10(-6)-10(-5) M) and SIN-1 (10(-6)-10(-5) M) on the responses to field stimulation. 3. Electrical field stimulation induced relaxation responses in the tracheal rings precontracted with histamine from control- and ethanol-treated rats. The relaxation responses induced by EFS were significantly reduced in the tracheal rings precontracted with histamine from ethanol dependent group. The responses induced by EFS in both groups were completely abolished by tetrodotoxin (1 microM), but unaffected by hexamethonium (1 microM). Incubation with D-arginine did not cause statistically significant increases in relaxation responses to EFS in both groups. L-Arginine (10(-6) M) caused statistically significant increases in relaxation responses to EFS in control rats, but not in ethanol dependent rats. Incubation with L-NAME (10(-6)-10(-5) M) caused statistically significant inhibition of the relaxation responses to EFS in both groups. SIN-1 (10(-6)-10(-5) M) induced significantly increase in relaxation responses to EFS in both groups. 4. Our results suggest that the possible mechanism responsible for inhibition of tracheal inhibitory responses to EFS in ethanol-dependent rats may be a reduction in production of NO and in the uptake of L-arginine.     

艾叶油的呼吸系统药理研究-Ⅱ,抗过敏作用

目的：本文研究艾叶油的抗过敏作用。方法：采用致敏豚鼠气管ＳｃｈｕｌｔｚＤａｌｅ 反应,组胺或氨甲酰胆碱引起的豚鼠气管收缩,大鼠被动皮肤过敏,５羟色胺引起的大鼠皮肤毛细血管通透性增强,豚鼠肺组织释放过敏性慢反应物质（ＳＲＳＡ） ,ＳＲＳＡ 收缩豚鼠回肠等试验。结果：艾叶油抑制致敏豚鼠气管ＳｃｈｕｌｔｚＤａｌｅ 反应（ＩＣ５０ ：９８ ．６ｍｇ／Ｌ） ;１００ｍｇ／Ｌ 明显降低组胺或氨甲酰胆碱引起的豚鼠气管收缩ｐＤ２ 值;明显抑制大鼠被动皮肤过敏（ＩＤ５０ ：０ ．２２ｇ／ｋｇ） 和５羟色胺引起的大鼠皮肤毛细血管通透性增强反应（ＩＤ５０ ：０ ．５２ｇ／ｋｇ） ;抑制豚鼠肺组织释放ＳＲＳＡ（ＩＣ５０ ：４９ ．７ｍｇ／Ｌ） ;拮抗ＳＲＳＡ 对豚鼠回肠的收缩（ＩＣ５０ ：３４ ．９ｍｇ／Ｌ） 。结论：艾叶油具有抗过敏作用,对呼吸道过敏反应有保护作用,是其治疗支气管哮喘和慢性气管炎作用机制之一     

硝酸甘油和一氧化氮对平滑肌的舒张作用

采用１００ｍｍｏｌ／Ｌ、３０ｍｍｏｌ／Ｌ氯化钾或组胺收缩的标本,研究了硝酸甘油和一氧化氮对豚鼠主动脉、气管和盲肠带的舒张作用．硝酸甘油在这些平滑肌上舒张作用强度依次为主动脉、气管和盲肠带,而一氧化氮的作用强度依次为主动脉、盲肠带和气管．亚甲蓝在１００ｍｍｏｌ／Ｌ、３０ｍｍｏｌ／ＬＫ＋和３×１０－６ｍｏｌ／Ｌ组胺收缩的主动脉标本上和由３×１０－５ｍｏｌ／Ｌ组胺收缩的气管标本上,可抑制一氧化氮和硝酸甘油的舒张作用,但不能在１００ｍｍｏｌ／Ｌ、３０ｍｍｏｌ／ＬＫ＋予收缩的气管标本上或在１００ｍｍｏｌ／Ｌ、３０ｍｍｏｌ／ＬＫ＋和组胺收缩的盲肠带标本上发挥抑制作用．结果说明,硝酸甘油和一氧化氮对血管平滑肌的舒张作用及对组胺收缩的气管的舒张作用与可溶性鸟苷酸环化酶有关,而对Ｋ＋收缩的气管及盲肠带的舒张作用则与可溶性鸟苷酸环化酶无关     

气管上皮嗜银细胞和5-羟色胺免疫反应细胞的定位

用银染色及免疫组织化学ＰＡＰ法，对狗、家兔、豚鼠、大鼠、小鼠气管粘膜上皮内嗜银细胞和５－羟色胺（５－ＨＴ）免疫反应（ｉｍｍｕｎｏｒｅａｃｔｉｏｎ）细胞的分布及形态进行观察。结果显示：５种动物气管上皮中均可见散在的嗜银细胞，家兔气管内嗜银细胞密度较大，而狗、大鼠的较少。５－ＨＴ－ＩＲ细胞仅见家兔、豚鼠、小鼠的气管粘膜上皮。气管中的内分泌细胞可分为开放型和闭合型，并可见旁突伸至邻近细胞。相邻切片观察未     

呼吸道异物取出术的麻醉体会

本文介绍支气管异物取出术采用静脉复合麻醉的方法、原则及其深度。特别强调麻醉诱导的平顺,术中持续高频正压人工给氧是手术成功和安全的关键。同时着重指出了手术方式,减少呼吸道损伤及苏醒快等问题。本组50例麻醉中,无一例死亡,术中术后经过平顺。     

人胚和鼠类气管裸鼠皮下移植

本实验在13只裸小鼠皮下移植BABC小鼠和Wistar大鼠气管及人胚气管、支气管,共26段。观察1～8周,移植气管的总存活率为77%。以气管裸鼠皮下移植为模型的实验,在10天以后加刺激因子比较适宜。