[Determination of samarium oxide and lanthanum oxide in the air of workplace by inductively coupled plasmamass spectrometry].

Objective: To establish a method for the determination ofsamarium oxide and lanthanum oxide by inductively coupled plasmamass spectrometryin the air of workplace. Methods: Samarium, lanthanum and their compounds in the air of workplace were collected through microporous filter. The samples were digested by nitricacid and perhydrol (V/V=4∶1) and detected by inductively coupled plasmamass spectrometry. Results: The linear range ofsamarium oxide and lanthanum oxide was 0-50.00 µg/L, Sm(2)O(3): y=0.0119x, r=0.9999; La(2)O(3): y=0.0617x, r=0.9998. The detection limits were less than 0.1 µg/L, and the minimum detection concentration were less than 1.52×10(-5) mg/m(3). The sampling efficiency were 100%, the recovery rates were 95.70%-102.01%, and the precision were 0.78%-1.58%. Conclusion: The indicators established in this study are conformed with the requirements of Chinese Occupational Standars of GBZ/T 210.4-2008, "The Guidelines for the Development of Occupational Hygiene StandarsMehods Part 4: Determination of Chemical Substances in the Air of Workplace".

[The diagnosis and treatment for pyriform sinus fistula in children].

Objective: To discuss the diagnosis and management for pyriform sinus fistula in children. Methods: Eight cases of pyriform sinus fistula admitted in Guangzhou Women and Children's Medical Center from May 2013 to August 2015 were retrospectively analyzed. The median age at onset was 54 months (range from 11 months to 12 years). All 8 cases presented recurrent neck infection (typical of redness, swelling, heat and pain) and 2 accompanied with acute suppurative thyroiditis. The diagnosis was confirmed by the preoperative barium esophagography combined with neck computed tomography scan (plain scan, enhancement and reconstruction). All the patients underwent laryngeal endoscopic-assisted surgery. Results: Preoperative imaging findings identified seven left-side cases and one bilateral (the symptom only manifested on left side). All 8 cases underwent left fistulectomy. There was no esophageal injury nor nerve injury during the operation. Postoperatively, all cases recovered well without complications (such as sound hoarse and coughing) and reoccurrence within the follow-up period (range from 7 months to 34 months). Conclusions: Preoperative barium esophagogram combined with neck computed tomography scan facilitates proper diagnosis and appropriate treatment. Laryngeal endoscopic-assisted technique at operation provides a better understanding of the anatomic relationship and the points where the fistulas penetrated into the pharynx, and essentially improves the operation outcome.

Effect and mechanism of different ways of transplanting bone marrow mesenchymal stem cells in cardiopulmonary resuscitation in rats.

The effect and mechanism of different ways of transplanting bone marrow mesenchymal stem cells (MSCs) were explored for treating cardiopulmonary resuscitation in a rat model. Rats were divided into the cardiopulmonary resuscitation group (Group Con), the stereotactic lateral ventricle transplantation group (Group LV), the internal carotid artery transplantation group (Group A), and the femoral vein transplantation group (Group V). MSCs were transplanted in Groups LV, A, and V. The MSC transplantation groups had a significantly higher neurological score than Group Con on days 3 and 7 after recovery (P < 0.05), and the Group LV score was the highest in all groups (P < 0.05). On day 3 after recovery, the MSC count of Group LV was significantly higher than those of Groups A and V (P < 0.01). On day 7 after recovery, the MSC count in the hippocampus of Group LV was significantly higher than those of Groups A and V (P < 0.05). On day 3 after recovery, the S100B level of Group LV was significantly lower than those of Groups A and V (P < 0.05). On day 7 after recovery, the S100B level was not significantly different between the MSC transplantation groups (P > 0.05). The expressions of vascular endothelial growth factor and brain-derived neurotrophic factor did increased significantly in the MSC transplantation groups on day 7 after recovery, particularly Group LV. Therefore, MSC therapy could significantly improve nerve function after cardiopulmonary resuscitation, and stereotactic lateral ventricle injection transplantation is an optimal method.

Effects of Ilexonin A on circulatory neuroregulation.

Ilexonin A (IA), a pentacyclic triterpene, has been semisynthesized in china for the first time. It is extracted from the root of Ilicis pubescentis, a commonly used herbal medicine in Guangdong for the treatment of cardiovascular, cerebrovascular and peripheral vascular diseases and heart failure with satisfactory effects. The pharmacokinetic studies indicated that the elimination half-life after oral and i.v. dosing were 17.7 +/- 2.4 h and 22.5 +/- 2.9 h respectively. The total clearance was 4.6 +/- 0.51/h. The bioavailability of IA capsules was 0.39 +/- 0.14 and LD50 was 234 mg/Kg. We have adopted modern techniques, including cellular electrophysiology, isotope tracing methods, molecular biology, electromicroscopy, etc., to probe into the pharmacologic mechanisms of the effects of IA on cardiovascular system. The results indicated that IA can increase the contractility of isolated guinea pig auricular myocardium, attenuate vascular smooth muscle tension induced by noradrenaline in the rabbit aorta. IA can exert a biphasic regulatory effect on arterial blood pressure. IA also can prolong A-V duration of Hiss bundle electrograph (HBE) in rabbits and prolong the action potential duration and the effective refractory period (ERP) of myocardial cells in guinea pigs. The results showed that IA can increase the cAMP content in the smooth muscle of aorta and exert a calcium-blockade effect. Therefore, the peripheral resistance vessels are relaxed and the cardiac afterload is lowered. IA-blocked calcium channels are correlated with both the potential-dependent channel and the receptor operated channel in vascular smooth muscles. IA also increases the cAMP content of myocardium and accelerates the cellular calcium influx and efflux, and this may be responsible for the direct mechanism of the positive inotropic action of IA. Under electron microscopy, it is observed that IA can alleviate the defect of succinate dehydrogenase in the myocardial mitochrondria of rabbit chronic congestive heart failure (CF) model and reduce the microstructural damage of the failed myodardium, therefore the anoxic tolerance of myocardium is increased, the effect of IA on the platelet stretching activity and microstructure in the patients with CF is also studied. It is found that IA can reduce the hypercoagulability of blood, decrease the severity of blood stagnation and improve the status of microcirculation. Effects of IA introventricular and cardiovascular central microinjection (nucleus tractus solitarius, paraventricular nucleus) on arterial blood pressure and heart rate were studied. It demonstrated that IA possess circulatory neuroregular effects by the medium of alpha-receptor and beta-receptor of cardiovascular motoneurons.