Neurotoxicity in operating room personnel working with gaseous and nongaseous anesthesia

Occupational exposure to high concentrations of anesthetic gases (more than 500 ppm of nitrous oxide and more than 15 ppm of halothane and enflurane) can cause neurobehavioral effects in operating room personnel. Factors such as stress and work organization play an additional role in reducing performance capacities. It is still unclear whether these conditions may become the predominant factor in behavioral impairment when exposure to anesthetic gases is reduced; in addition, we wished to ascertain the extent of neurobehavioral and neuroendocrine effects at relatively low levels of exposure to such gases. Therefore the same group of 30 operating room personnel was examined with neurobehavioral tests during gaseous and nongaseous anesthesia. In this way, the neuropsychological performance was examined under the same stress conditions, but with different exposure levels to anesthetic gases. Serum cortisol was measured as an additional biological stress indicator. Prolactin secretion was examined to study possible interference of anesthetic gases with the dopaminergic system. The results were compared with those in a control group of 20 hospital workers from other departments, with similar characteristics in respect of age, sex, and education. During work with gaseous anesthesia, average airborne concentrations (geometric mean) of nitrous oxide were 50.9 ppm (SD 20.8) on the first day of the working week and 54.2 ppm (SD 22.1) on the last day of the working week, whereas average urinary nitrous oxide (geometric mean) were 21.54 g/l on the first day of the working week and 25.67 g/l on the last day of the working week. The operating room workers showed slower reaction times at the end of the week with gaseous anesthesia, compared with workers using nongaseous anesthesia and the control group. At the same time they also showed increased secretion of prolactin, whereas cortisol remained unchanged. Therefore, it can be concluded that lower levels of exposure to anesthetic gases (and not only high exposure levels) cause an impairment of neurobehavioral performance, with the action of stress being less relevant. The mechanism of anesthetics' neurotoxic action seems to be related to interference with the dopaminergic system.     

Urinary excretion ofD-glucaric acid,an indicator of drug metabolizing enzyme activity,in patients with impaired renal function

Summary The urinary excretion rate ofD-glucaric acid, an in vivo parameter of the activity of drug metabolizing enzymes, has been determined in patients with chronic renal insufficiency (glomerular filtration rate 4.5–80 ml/min/1.73 m²). The mean value of 22.3 µmoles/d (SD 7.2; n 28) was almost identical to that of healthy controls (22.1 µmoles/d, SD 7.3; n 22). Thus, no inhibitory or enhancing effect of renal insufficiency could be detected. The ability of this parameter to indicate alterations in the activity of hepatic drug metabolism, even in patients with renal insufficiency, was demonstrated by the increased excretion rate of glucaric acid (107 µmoles/d, SD 43.5; n 8; p<0.001) after treatment for 7 days with the enzyme inducer phenobarbital. No significant correlation was found between glucaric acid excretion and sex, age, body weight or body surface in 50 patients. Glucaric acid excretion, therefore, should not be related to the creatinine content of urine samples, since creatinine excretion decreases with severity of renal insufficiency and varies with sex, age, body weight and many other conditions. A single dose of dipyrone (Novalgin^®), a further in vivo indicator of drug metabolism, increased glucaric acid excretion on the same day, but no interference was found after a single dose of cortisol.     

Salivary electrolytes and digitalis

The hypothesis that an increase in salivary concentration ofcertain electrolytes (Ca x K) is a sign of digitalis intoxicationwas tested in 16 untreated health volunteers, 29 digitalisedheart failure patients and four further healthy volunteers givendigoxin. Salivary electrolyte levels were raised in only abouthalf the digitalised patients and blood levels of digoxin werenot always higher in these patients than in those with normalelectrolyte concentrations. The salivary electrolyte levelsof the healthy volunteers given digoxin remained normal. Thesefindings would seem to rule out the possibility that digitalisis responsible for the changes in salivary electrolytes observedin certain cases of heart failure. A very marked correlation(P<0.00002 by Fisher's exact probability test) was found,however, between an increase in the product of salivary calciumand potassium (Ca_sal x K_sal) and the presence of clinical signsof poorly compensated heart failure. It is suggested that thismight be a result of adrenergic stimulation, which is knownto occur in heart failure, affecting the salivary glands.     

Effects of sympathectomy on the in vivo α and β-responses of the parotid gland

Summary Salivary secretion in response to noradrenaline and isoprenaline was measured in innervated and chronically sympathectomized parotid glands of the rat. In innervated glands, the responses to isoprenaline lasted longer than those to noradrenaline. Chronic sympathetic denervation enhanced the responses to both noradrenaline and isoprenaline. The magnitude of the supersensitivity to isoprenaline was related to the dose and the time at which the responses were analyzed. Supersensitivity was greater for the initial than for the total secretion elicited by isoprenaline. Propranolol (1 mg/kg) and phenolamine (5 mg/kg) were used in order to determine the relative participation of and -adrenoceptors in the enhanced responses to isoprenaline. The results suggest that postjunctional supersensitivity for the secretory responses of this organ to isoprenaline is mainly mediated through -adrenoceptors of the secretory cells and -adrenoceptors of the myoepithelial cells.     

吗啡依赖及戒断大鼠糖皮质激素及其受体mRNA表达水平的改变

目的:研究慢性吗啡处理和吗啡戒断对大鼠血清中ACTH及其受体mRNA表达水平的影响。方法:利用放射免疫法测定吗啡依赖及戒断大鼠血清中ACTH及皮质醇的浓度;利用核酸分子杂交技术研究下丘脑糖皮质激素受体(GR)基因表达的改变情况。结果:(1)吗啡依赖组大鼠血清中ACTH及皮质醇的浓度明显低于对照组;戒断d1大鼠血清ACTH浓度仍明显低于对照组(P<0.01),但血清皮质醇的浓度则明显高于对照组(P<0.01);戒断d7大鼠血清ACTH浓度与对照组比较,无显著性差异(P>0.05),而血清皮质醇的浓度仍略高于对照组(P<0.05);(2)吗啡依赖组大鼠下丘脑GR基因表达水平下降(P<0.05),戒断组大鼠GR的基因表达均高于对照组,但无显著性差异(P>0.05)。结论:吗啡类物质的长期使用可以对下丘脑-垂体-肾上腺轴的激素分泌功能及GR的基因表达产生明显的抑制作用。     

抑癌基因PTEN在口腔涎腺腺样囊性癌组织中的表达

目的　从蛋白水平研究抑癌基因 10号染色体缺失的磷酸酯酶及张力蛋白同源物 (PTEN ) ,在口腔涎腺腺样囊性癌中表达及其意义。方法　采用免疫组织化学方法检测 3 4例腺样囊性癌 (其中筛孔型 14例 ,管状型 11例 ,实体型 9例 )组织中PTEN的表达。结果　 3 4例腺样囊性癌PTEN蛋白表达阴性率为 17.6% ( 6/ 3 4) ,筛孔型、管状型、实体型表达阳性率分别为 14 .3 % ( 2 /14 ) ,18.2 % ( 2 / 11)和 2 2 .2 % ( 2 / 9) ,各型之间阳性率无显著性差异 (P >0 .0 5 )。结论　涎腺腺样囊性癌组织中存在抑癌基因PTEN表达缺失 ,PTEN在部分腺样囊性癌病变发展中起作用 ,PTEN表达异常与腺样囊性癌分型以及临床病理特征无关     

扁桃体周脓肿感染途径的探讨

为探讨扁桃体周脓肿的真正发病机理、感染途径，对连续诊治的１３１例扁周脓肿患者进行研究。其中８３例患侧的扁桃体被切除，切除之扁桃体外侧面均平整。通过８３例组织学观察，扁桃体上极表面既无扁桃溃破亦无脓瘘，邻接扁桃体上方之软腭粘膜下发现有感染及／或纤维化的小唾液腺（Ｗｅｂｅｒ腺），这些与扁桃体相邻的腺体在其他非扁周脓肿患者则显示正常形态与结构。从而认为扁桃体周围的化脓性感染可能与Ｗｅｂｅｒ腺有关，而非急性扁桃体炎。主张早期扁桃体切除术治疗扁周脓肿，目的在于获得充分引流。     

Randomised trial of dopamine compared with hydrocortisone for the treatment of hypotensive very low birthweight infants

AIM—To compare the efficacy of hydrocortisone with dopamine for the treatment of hypotensive, very low birthweight (VLBW) infants.METHODS—Forty infants were randomly allocated to receive either hydrocortisone (n=21) or dopamine (n=19).RESULTS—All 19 infants randomised to dopamine responded; 17 of 21 (81%) did so in the hydrocortisone group. Three of the four non-responders in the hydrocortisone group had clinically significant left to right ductal shunting. The incidence of bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, symptomatic patent ductus arteriosus, hyperglycaemia, sepsis (bacterial or fungal) or survival did not differ between groups. The adrenocorticotrophic hormone (ACTH) stimulated plasma cortisol activity, either before or after treatment, did not differ between the two groups of infants. Although a significant difference in efficacy between dopamine and hydrocortisone was not noted (P = 0.108), there were four treatment failures in the hydrocortisone group, compared with none in the dopamine group.CONCLUSION—Both hydrocortisone and dopamine are effective treatments for hypotension in very low birthweight infants.     

Induction of Squamous Cell Carcinomas in the Salivary Glands of Rats by Potassium Iodide

In a 2-year carcinogenicity study of potassium iodide (KI) in F344/DuCrj rats, squamous cell carcinomas (SCCs) were observed in the salivary glands of 4/40 males and 3/40 females receiving 1000 ppm KI in the drinking water. Ductular proliferation with lobular atrophy was observed at high incidence in the submandibular glands of the high-dose animals, and squamous metaplasia was frequently evident within the proliferative ductules and the larger interlobular ducts. A transition from metaplasia to SCC was apparent. The results suggest that squamous metaplasia in proliferative ductules, occurring secondarily to lobular impairment induced by KI, may develop into SCCs via a non-genotoxic, proliferation-dependent mechanism.     

灵芝孢子粉提取物降血糖作用及机制的实验研究

用Ｓｔｚ复制大鼠糖尿病模型观察了灵芝孢子粉乙醇提取物的水溶部分（Ｇｌｓｅ）的降糖作用及其对胰岛素离体生物活力和内分泌激素Ｉｎｓ、ＧＨ、Ｃｏｒ的影响。实验结果表明Ｇｌｓｅ（相当生药６２５０ｍｇ／ｋｇ）对糖尿病大鼠有明显的降低血糖作用，增强耐糖效应，对Ｓｔｚ损伤有一定的对抗作用，促进糖尿病大鼠的Ｉｎｓ分泌，维持ＧＨ、Ｃｏｒ的正常水平。含药血清对胰岛素离体生物活力无明显影响