油页岩及其矿渣的致突变研究

采用Ames试验、E Coli大肠杆菌突变试验和动物骨髓细胞微核试验对油页岩及其矿渣提取物进行了致突变性鉴定。结果表明油页岩及其矿渣提取物在微核试验中呈阳性反应,而在细菌回变试验中呈阴性反应。     

THE EFFECT OF SOME α2-ADRENOCEPTOR AGONISTS AND ANTAGONISTS ON GASTROINTESTINAL TRANSIT IN MICE: INFLUENCE OF MORPHINE, CASTOR OIL AND GLUCOSE

1. The effects of graded doses of the α₂-adrenoceptor agonists clonidine, tizanidine and BHT-920, and the α₂-adrenoceptor antagonists yohimbine and idazoxan, on gastrointestinal transit were investigated in mice using the charcoal meal test. 2. The agonists produced significant and dose-dependent decreases in gastrointestinal transit, and the antagonists produced the opposite effect. In affecting the gastrointestinal transit, clonidine (1 mg/kg) was as effective as tizanidine (12 mg/kg) and BHT-920 (40 mg/kg), while yohimbine (2 mg/kg) was as effective as idazoxan (1 mg/kg). 3. Morphine (2, 4 and 8 mg/kg) significantly inhibited gastrointestinal transit. This effect was significantly reversed by the co-administration of yohimbine (2 mg/kg) and idazoxan (1 mg/kg). 4. The acute administration of glucose (5.04 g/kg, i.p.) potentiated the inhibition of gastrointestinal transit produced by clonidine (1 mg/kg) and BHT-920 (40 mg/kg). Glucose treatment, however, had no significant effect on the increase in gastrointestinal transit induced by yohimbine (2 mg/kg) or idazoxan (1 mg/kg). 5. Castor oil (0.25 mL/mouse, orally) induced diarrhoea in saline-treated animals within about 45 min. Clonidine (1 mg/kg), tizanidine (12 mg/kg) and BHT-920 (40 mg/kg) delayed the occurrence of diarrhoea to 2.1, 1.2 and 1.4 h, respectively.     

烹调油烟对机体健康的危害

烹调油烟气含有２００多种有害气体。实验研究和流行病学调查表明：油烟气可损伤肺部功能，引起机体免疫功能下降，并具有致突变性和致癌性，是肿瘤发生的可疑因素。     

天津市煎炸油卫生状况评价

通过连续８小时的煎炸实验和对市，郊２９个煎炸点的现场卫生学调查及采用羰基值（ＣＯＶ），极性组分（ＰＣ）对所采样品的分析表明，天津煎炸油的总体的卫生质量基本符合国家卫生标准，参考极性组分的ＡＤＩ值并依据本次调查结果，估计天津大部分居民的煎炸食品摄入量安全水平，但对于偏爱煎炸食品者其安全系数明显下降。     

Isoflurane for removal of chest drains after cardiac surgery

Thirty-five patients who had undergone uncomplicated cardiac surgery were randomly allocated to receive either Entonox or isoflurane 0.25% in Entonox as inhalational analgesia for the removal of their two chest drains. The gases were presented premixed in high-pressure cylinders and were self-administered by means of a demand valve. The removal of the second drain was more painful than the first but that pain was better controlled by isoflurane 0.25% in Entonox than by Entonox alone.     

Mortality studies of machining fluid exposure in the automobile industry III: A case-control study of larynx cancer

A case-control study of larynx cancer was conducted within a cohort of automobile workers exposed to metal working fluids, commonly referred to as machining fluids (MF). Results are based on 108 cases of larynx cancer and 5:1 matched controls. Risks associated with specific types of MF, as well as specific components of the fluids were evaluated. Based on a retrospective exposure assessment, lifetime exposures to straight and soluble fluids, grinding particulate, biocides, selected metals, sulfur, and chlorine were examined. Exposure to asbestos and acid mists at two of the three study sites was also characterized. Results suggest that straight mineral oils are associated with almost a two-fold excess in larynx cancer risk. There was also evidence of an association with elemental sulfur, commonly added to straight MF to improve the integrity of the materials under extreme pressure and heat. It is not clear whether sulfur is causally related to an excess relative risk of larynx cancer or whether the observed association is the result of unmeasured confounding by another contaminant or process feature. For example, the high stress operations that require MF enriched with sulfur are also more likely to produce polycyclic aromatic hydrocarbons (PAHs) during the process. Thus, the observed association with sulfur may be due to an association with PAH. The finding of excess risk of laryngeal cancer associated with MF is consistent with several previous reports in the literature. This is the first study, however, to distinguish straight mineral oils from other types of MF. Based on these findings, a general reduction in concentrations of straight mineral oil particulate in occupational environments would be prudent.     

Occupational exposure of deck crews to carcinogenic agents on crude oil tankers

Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated.     

川芎挥发油化学成分研究

采取闪蒸气相毛细管色谱法和气相毛细管色谱—质谱法研究了宁夏六盘山区产川芎的挥发油化学成分,色谱分离出50多个峰,质谱鉴定了24个成分,主要是川芎酜内酯(46.37％)、丁基酞内酯(13.87％)、新蛇床内酯(6.98％)和丁烯基酜酯(4.8％)。红外光谱图中有较强的内酯特征吸收峰,为质谱所鉴定的以上主要成分提供了佐证。将闪蒸气相色谱法与蒸气蒸馏提取气相色谱法进行对照,二者的色谱图基本相符,前者是分析天然产物挥发性成分更加简便、迅速的微量方法。     

Evaluation of awakening and recovery characteristics following anaesthesia with nitrous oxide and halothane fentanyl or both for brief outpatient procedures in infants

This study compared recovery characteristics and postoperative ventilatory function when halothane, fentanyl or combination of halothane and fentanyl in addition to N₂O were used for intraoperative anaesthesia in term infants undergoing hernia repair as outpatients. Sixty-six full term ASA PS I infants ages 1–12 months were studied. All received inhalation induction with N₂O, O₂ and halothane, followed by intravenous atropine and atracurium, tracheal intubation, and controlled ventilation. For anaesthesia maintenance, patients were randomized into one of three groups. Group I received 70% N₂O, 30% O₂ and halothane. Group II received 70% N₂O, 30% O₂, halothane and 2 μg·kg^?1 fentanyl. Group III received 70% N₂O, 30% O₂ and 10 μg·kg^?1 fentanyl. Awakening times were similar in all three groups, however, Group I patients had significantly shorter recovery and discharge times than those of Group II and III. None of the patients experienced postoperative apnoea or periodic breathing. One patient in Group III experienced two brief episodes of bradycardia not associated with apnoea or arterial desaturation (Spo ₂ >90% for greater than 30 s). Decreased Spo ₂ occurred less frequently in Group I (5.9%) compared to Group II (22.7%) and Group III (19.0%) patients, however, the group differences were not significant. Transcutaneous CO₂ (TcCO₂) values were not statistically different among the three groups. Pain scores were initially lower in Groups II and III, but at 120 min the differences were not significant. Postoperative apnoea was not observed in this study. Spo ₂ <90% and TcCO₂ >9 kPa (70 mmHg) was more common in infants receiving 2 and 10 μg·kg^?1 fentanyl than in infants receiving halothane and nitrous oxide anaesthesia. Infants <3 months old did not have a higher incidence of Spo ₂ <90% or significantly higher TcCO₂ values when compared to infants >3 months old. Fentanyl in doses used in this study did not prolong awakening time but did prolong recovery and discharge times in outpatient infants.     

Should nitrous oxide be discontinued before desflurane after anaesthesia with desflurane/N2O?

Background : The appearance of hypoxaemia immediately after anaesthesia with nitrous oxide may be partially explained by diffusion hypoxia. This study was undertaken to evaluate circulatory and respiratory variables during emergence after desflurane/nitrous oxide anaesthesia, and whether there are any differences depending on which gas is discontinued first. Methods : 20 patients were studied after gynaecological laparoscopic surgery. The depth of anaesthesia was reduced 10 min prior to the emergence by stopping the administration of one of the two inhalational agents. Desflurane was discontinued first in Group 1, nitrous oxide in Group 2. Ventilation was controlled with E'C0₂ maintained at 5% until the administration of the second anaesthetic gas was discontinued. Thereafter, the patients breathed spontaneously. Results : The PaC0₂ at which the respiratory drive reappeared after controlled normoventilation was similar in both groups, 6.1–6.5 kPa, and extubation was performed after 10–11 min. At extubarion, the end–tidal C0₂ and total MAC were similar in the groups, about 6.2 vol% and 0.16, respectively. Mean arterial blood pressure was significantly higher in Group 1. The cardiac output increased in both groups from about 6 1/min at the conclusion of anaesthesia to 9.0 and 7.6 1/min at 15 min in the recovery period. End–tidal O₂ decreased and CO₂ increased in both groups during the first 10 min in the recovery period. pH was reduced at 15 and 30 min in both groups. Conclusion : Irrespective of which agent was discontinued first, there was an increase in cardiac output, decrease in oxygenation and a modest acidosis in the first 30–min recovery period. The only significant difference between the groups was in mean arterial blood pressure in the early emergence phase with a greater MAP when N₂O had been used until the conclusion of anaesthesia.