Children's Health and the Environment—The First Herbert L. Needleman Award Lecture

Children today are exposed extensively to toxins in the environment. Prominent among these are exposures to over 70,000 synthetic chemicals, all newly developed in the past 50 years and largely untested for their hazards to children's health. Children are uniquely vulnerable to toxins, and with increasing incidence they are developing chronic, disabling, life-threatening diseases known or suspected to be of environmental origin–asthma, endocrine disruption, cancer, and the diseases caused by tobacco. Pediatricians need to consider toxic etiologies in the differential diagnosis of childhood illness.     

烟溶液与温石棉对细胞增殖活性的影响

目的　探讨香烟烟雾溶液与温石棉单独及联合作用对细胞增殖活性的影响。方法　将人胚肺（ Ｈ Ｅ Ｌ） 成纤维细胞用不同浓度的烟溶液和温石棉单独及联合作用一定时间后,应用［３ Ｈ］ Ｔｄ Ｒ参入法测定了细胞的增殖能力。结果　低剂量的烟溶液与温石棉单独作用时均可促进细胞的增殖,但较高剂量的烟溶液和温石棉则可抑制细胞的增殖;当二者联合作用时,低剂量的烟溶液与温石棉可协同增加细胞的增殖,而较高剂量的烟溶液与温石棉则只表现为相加作用。结论　烟溶液与温石棉单独及联合作用均可影响 Ｈ Ｅ Ｌ细胞的增殖活性,但其促增殖和抑制增殖能力则随剂量不同而不同。     

Preliminary study of electrocautery smoke particles produced in vitro and during laparoscopic procedures

Background: The objective of this preliminary study was to describe the particles contained in cautery smoke produced during five laparoscopic procedures and verify the collection method during three laboratory experiments on ex vivo animal tissue. Methods: A cascade impactor collected the smoke according to particle size, and particle weights were calculated on an electronic microbalance. Electron microscopic analysis and energy dispersive X-ray evaluation were used to determine particle morphology and elemental composition. Results: The particles, distributed according to size on the seven rotating trays of the impactor, had diameters ranging from 0.05 to >25 m, with most being 0.1–1 m. In vitro experiments yielded more particles, especially larger (>5 m) ones, than the surgical procedures, because the cauterized specimens could be placed much closer to the cascade impactor in the laboratory environment, eliminating most obstacles to particle recovery. In the laparoscopic surgery patients, larger particles, because of their physical properties, were more likely to remain trapped in the abdomen or to drop off in the collection apparatus. Uniformly, two populations of particles were demonstrated—either large, irregular fragments (2–25 m) rich in carbon and oxygen, suggesting structural cellular components, or small homogeneous spheres (0.1–0.5 m) composed of sodium, magnesium, calcium, and potassium salts. Conclusions: This study demonstrates the presence of breathable areosols and cell-size fragments in the cautery smoke produced during laparoscopic procedures. Their exact chemical composition and potential adverse effects for patients and personnel are not known.     

Characteristics of tetrahydrocannabinol (THC)-produced discrimination in rats

Rats were trained in a T-shaped maze to discriminate the effects produced by i.p. injections of tetrahydrocannabinol (THC) and the no-drug state (state-dependency, StD). Several doses of both ⁸-THC (range: 0.75–5.0 mg/kg) and ⁹-THC (range: 0.75–10.0 mg/kg) were used in order to compare the number of sessions required by the animals until reaching criterion performance. An additional group of rats had to discriminate pentobarbital sodium (20.0 mg/kg) from the no-drug state.Results: THC discrimination was proportional to dose i.e., animals that had to differentiate high doses of THC from no drug acquired the T-maize task faster than animals trained with the lower doses of THC. Acquisition data further suggest that ⁸-THC is somewhat less potent than the ⁹-isomer. ⁹-THC (10.0 mg/kg) produces strong StD, as defined by Overton (1971), since both this group and the barbiturate group reached the criterion within the first 10 training sessions. Time and dose testings suggest that stimulus properties of drugs vary in a quantitative way and that the calculated ED₅₀ values are mainly determined by the training dose used. It was found that the higher the training dose used the higher was the corresponding ED₅₀ value. Hashish smoke can maintain drug responding among THC-trained rats. A lowered content of brain catecholamines and/or serotonin, induced by AMPT (150 mg/kg) and PCPA (310–350 mg/kg), did not lessen ⁹-THC (2.5 mg/kg) discrimination.Portions of the results were presented at the Fourth Scandinavian Meeting on Physiology and Behavior, Oslo May 22–24, 1975.     

第二信使系统和其介导的基因表达对针灸效应影响的研究

从微观水平研究针灸效应对揭示其机理有重要的意义。本文从第二信使系统和其介导的基因表达对针灸效应影响的研究方面综述了针灸效应的终结反映于细胞内生物效应的变化(即对机体不同器官组织细胞内的物质代谢调节 ) ,从一个侧面提示 ,针灸对机体各系统的调节作用最终是在细胞通过胞内信息传导系统实现的     

Injury of Mouse Brain Mitochondria Induced by Cigarette Smoke Extract and Effect of Vitamin C on It in vitro

Objective To investigate the toxicity of cigarette smoke extract (CSE) and nicotine on mouse brain mitochondria as well as the protective effect of vitamin C in vitro. Method Mouse brain mitochondria in vitro was incubated with CSE or nicotine in the absence or presence of vitamin C for 60 minutes, and the changes of mitochondrial function and structure were measured. Results CSE inhibited mitochondrial ATPase and cytochrome C oxidase activities in a dose-dependent manner.However, no significant changes in the peroxidation indices were observed when mitochondrial respiratory enzymes activity was inhibited, and protection of mitochondria from CSE-induced injury by vitamin C was not displayed in vitro. The effect of CSE on mouse brain mitochondria swelling response to calcium stimulation was dependent on calcium concentrations. CSE inhibited swelling of mitochondria at 6.5 μmol/L Ca^2 , but promoted swelling response at 250μmol/L Ca^2 . Nicotine, the major component of cigarette smoke, showed no significant damage in mouse brain mitochondria in vitro. The CSE treatment induced mitochondrial inner membrane damage and vacuolization of the matrix, whereas the outer mitochondrial membrane appeared to be preserved. Conclusion The toxic effect of CSE on brain mitochondria may be due to its direct action on enzymatic activity rather than through oxygen free radical injury. Nicotine is not the responsible component for the toxicity of CSE to brain mitochondria.     

被动吸烟对不同孕期大鼠宫内胚胎发育影响研究

采用被动吸烟方法研究了香烟烟雾对不同孕期大鼠宫内胚胎发育的毒性和影响。结果表明：香烟烟雾对孕鼠胚胎有明显的毒性，可引起胚胎死亡、畸形和宫内生长迟缓（ＩＵＧＲ）；且孕期不同，这种毒性和影响的后果也不同：其中从孕１天即开始被动吸烟的Ａ组主要表现为死胎、吸收胎和ＩＵＧＲ，且发生率非常显著地高于对照组（Ｐ〈０．０１）；孕８天开始被动吸烟的Ｂ组则主要为畸胎和ＩＵＧＲ，其发生率也比对照组有显著升高（Ｐ〈０．０     

A European validation study of smoking and environmental tobacco smoke exposure in nonsmoking lung cancer cases and controls

Objectives: The purpose of this study was to validate, in a case-control study, the reporting by lung cancer cases and controls of their own lifetime smoking habits and of the smoking habit of the spouse. Methods: In a multicenter (Sweden, Spain, Italy) case-control study of environmental tobacco smoke (ETS) and lung cancer, subjects were screened by repeated probing to exclude regular smokers of one cigarette/day or more for one year or more, and to quantify any occasional smoking. We then performed a short validation interview with next-of-kin in three centers. Results: Only five of 408 index subjects who had never smoked regularly (1.7 percent) were reported by next-of-kin to be former regular smokers. These subjects had a cumulative lifetime consumption of cigarettes below 1.1 pack years. Among 351 subjects with quantitative smoking information from both sources who reported ever smoking 400 cigarettes or less (the definition of never-smoker used in the multicenter ETS study), nine subjects (2.6 percent) had smoked more than this amount occasionally according to next-of-kin. Misclassification was not higher for cases than controls. Relative risks for lung cancer associated with indicators of ETS exposure were not substantially altered by excluding the nine possibly misclassified subjects. The reports from 223 pairs of index subjects and next-of kin regarding the cumulative amount smoked by the spouse agreed quite well (Spearman's rank correlation 0.75 for reported smokers, 0.92 for all subjects). Only one index subject failed to report a spouse who had smoked regularly (99 percent sensitivity). Conclusions: Smoking status and exposure to spousal ETS as reported by lung cancer cases and controls agreed strongly with reports by next-of-kin. Overall, our results suggest that bias from smoker misclassification is likely to be insignificant, and they contribute to the evidence linking exposure to ETS with an increased risk of lung cancer.