Chronic occupational exposure to organic solvents

Summary Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brake-hoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m³ (22.3 ppm), 68.6 mg/m³ (18.6 ppm) and 11.3 mg/m³ (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10–31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m³).     

临床肿瘤用药的统计分析

[目的]了解肿瘤用药的消费现状及发展趋势，为临床合理用药提供依据。[方法]对本院1996年-2002年抗肿瘤药、生物反应调节剂和升白细胞药的用药情况进行统计分析，以药品的年消耗金额作统计。[结果]抗肿瘤药、生物反应调节剂和升白细胞药分别占全部药品年消耗总金额的24．24％～33．73％、15．80％～23．33％和5．86％～9．11％。[结论]抗肿瘤药、生物反应调节剂和升白细胞药是用于肿瘤治疗的主要药品，尤其是抗肿瘤天然药物有着广阔的应用前景。     

部分创面外用抗菌药物与成纤维细胞生长因子2、表皮生长因子、重组人生长激素对成纤维细胞生物学特性影响的实验研究

目的观察部分创面外用抗菌药物与成纤维细胞生长因子(FGF)2、表皮生长因子 (EGF)、重组人生长激素(rhGH)对成纤维细胞生物学特性的影响。方法体外培养成纤维细胞, 按所加药物不同分为对照组(常规培养)、丁胺卡那霉素(0．021、0．210、2．100 mg/L)组、庆大霉素(5、 50、500 mg/L)组、氯霉素(0．01、0．10、1．00 mg/L)组、磺胺米隆(5、10 g/L)组、FGF2(2 400 U/ml)组、 EGF(2 000 U/ml)组及rhGH(0．016、0．160、1．600 g/L)组。用噻唑蓝(MTT)法测定各组成纤维细胞增殖活性[吸光度(A)值],用流式细胞仪检测细胞周期,并于显微镜下观察细胞形态的变化。结果 (1)MTT法检测:与对照组A值0．455 3±0．021 7比较,各种剂量丁胺卡那霉素组、庆大霉素组、氯霉素组、磺胺米隆组成纤维细胞A值均明显降低(P<0．05或0．01),其中磺胺米隆(5、10 g/L)组降低最明显,分别为0．101 3±0．001 1、0．095 0±0．004 1(P<0．01)。FGF2组及0．016 g/L rhGH 组细胞A值明显高于对照组(P<0．05),而EGF组及0.160、1．600 g/L rhGH组A值与对照组接近 (P>0．05)。(2)细胞周期检测:对照组细胞增殖指数(PI)为(9．63±0．45)％,与之比较,0．210 mg/L丁胺卡那霉素组细胞PI值无明显变化(P>0．05),FGF2组、EGF组及0．016 g/L rhGH组PI值均明显升高,分别为(46．76±2．33)％、(42．30±1．41)％、(13．29±0．47)％(P<0．05或0．01)。 (3)形态学观察:对照组、EGF组及0．160、1．600 g/L rhGH组成纤维细胞数目较多,呈长条形或梭形, 轮廓不清,透明度高;丁胺卡那霉素组、庆大霉素组、氯霉素组、磺胺米隆组细胞数目较少,形态不规则,轮廓清晰,透明度低,细胞内多有颗粒样物质及空泡;FGF2组、0．016 g/L rhGH组细胞分布均匀、密集,呈长条形或梭形,核分裂相多见,轮廓不清,透明度高。结论不同创面外用药物对成纤维细胞生物学特性的影响各异,在创面修复过程中应选择合适的创面外用药物,以促进愈合并抑制瘢痕增生。     

F344／N－Smu－D大鼠生长发育若干生物学特性的检测

Ｆｉｓｃｈｅｒ３４４大鼠在国外广泛应用于肿瘤研究与慢性毒性试验，八十年代中期引入我国。我们对Ｆ３４４／Ｎ－Ｓｍｕ－Ｄ大鼠的生长发育的若干生物学特性进行了检测。结果表明，该品系大鼠体型较ＳＤ大鼠与Ｗｉｓｔａｒ大鼠小，除睾丸、垂体、肾上腺、乳腺外的大部分器官与组织的自发性肿瘤的发生率相对较低，将Ｆ３４４／Ｎ－Ｓｍｕ－Ｄ大鼠种群与Ｆ３４４／ＤｕＣｒｊ种群比较，在体重、耗食量，血液学与生化学等方面的若干特性差异较大，肿瘤发生率与死亡差别不大。     

单宁酸处理带瓣牛颈静脉的生物学评价

目的从生物学角度评价单宁酸处理的带瓣牛颈静脉是否符合国家医用材料的要求。方法带瓣牛颈静脉经单宁酸处理后按国家医用材料的要求进行浸提液的制备、细胞毒性试验、过敏试验、皮内刺激试验、原发性皮肤刺激试验、溶血试验、急性全身毒性试验及热原试验等生物学评价试验。试验方法均参照《医用有机硅材料生物学评价试验方法》GB／T16175-1996。结果培养的L-929小鼠成纤维细胞经含浸提液的培养基培养后形态良好，增值旺盛，材料细胞毒性评级为0～1。无皮肤刺激反应和过敏反应，皮内刺激试验PⅡ（原发性刺激指数）为0．4，和阴性对照组差异无统计学意义。全身毒性实验受试动物未出现毒性症状。溶血试验溶血率0．7％，符合国家标准（〈5％）。热原试验经中国药品生物制品检定所检定，单宁酸处理后带瓣牛颈静脉无热原（样品批号：060802017）。结论单宁酸处理的带瓣牛颈静脉符合国家医用材料的要求，可以植入人体。     

Age, lens transmittance, and the possible effects of light on melatonin suppression

Recently it has been suggested that a previously undetected, rhodopsin-based, visual pigment, located in some retinal ganglion cells and having a peak sensitivity around 460 nm, may be responsible for light-induced melatonin suppression and, perhaps, maintenance of the circadian rhythm. Using data from the literature, it is shown that, as absorption in the crystalline lens for shorter visible wavelengths increases substantially with age, while the pupil diameter tends to decrease, the effective retinal exposure received under the same ambient lighting conditions by the pigment is almost 10 times lower in an old, as compared with a young, eye. Interestingly, replacement of the old crystalline lens by an intraocular implant restores the exposure to youthful levels. The possible effects of these changes with age on circadian rhythms are discussed.     

Occupational chronic exposure to metals

Summary Stainless steel welders (n = 103) were examined. To estimate external exposure, personal air sampling was used. Internal exposure was quantified by the determination of nickel levels in erythrocytes, plasma and urine. Men and women (n = 123) were examined for control purposes. In the plasma and erythrocytes of the controls the nickel concentration was below the level of detection (< 1.81 μg/l). The element concentrations in urine were between < 0.1 and 13.3 μg/l. Of the controls 95% showed nickel levels in urine below 2.2 μg/l (reference value). The average concentration of nickel in the air was 93 ± 81 μg/m³. The average concentration of nickel in the plasma samples was 4.9 ± 4.0 μg/l (95th percentile 12.8 μg/L). In erythrocytes nickel could not be detected. The nickel concentrations in the urine of the welders were 18.5 ± 28.5 μg/l on average (95th percentile 52.5 μg/l). Only a weak correlation between the nickel levels of plasma and urine could be detected (C_urine = 2.07 + 8.45 C_plasma; r = 0.294; p < 0.01). Based on our results and on the reported literature a future limit value for the nickel concentration in urine should lay between 30 and 50 μg/l. This value corresponds to an external exposure of 500 μg nickel per cubic metre.     

Biological exposure limits estimated from relations between occupational styrene exposure during a workweek and excretion of mandelic and phenylglyoxylic acids in urine

Summary Styrene exposure of 18 workers in fiber-glass reinforced plastic industries was measured for 30-min periods throughout each workday for a week. The styrene uptake was estimated using pulmonary ventilation measurements. All urine voidings were collected separately and the styrene metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined. The relationship between both exposure and uptake versus excretion of these metabolites was studied. Styrene metabolite concentrations and excretion rates (with 95% tolerance limits) were calculated to correspond to a constant 8-h exposure at the Swedish exposure limit level (25 ppm) or an uptake of an exposure limit related styrene dose (6.3 mmol). The tightest tolerance limits were obtained for excretion rate of MA + PGA per 24 h. The calculated biological exposure limit was 3.4 (± 0.7) mmol MA + PGA/24 h for a dose of 6.3 mmol styrene.     

健康人携带的白喉棒状杆菌生物学性状分析

目的：探讨健康人携带的白喉棒状杆菌的生物学特性及其与标准的产毒菌株的生物学性状的差异。方法：采用鸡蛋斜面培养基，亚碲酸钾血琼脂平板和肉汤培养基观察其生长特性，测定多种系列化反应性，毒力和药物敏感性。结果：健康人携带的白喉杆菌的培养特性典型均无毒力；发酵麦芽糖和发酵蔗糖的菌株较多，有较多的耐麦迪霉素，苯唑青霉素和洁霉素的菌株。结论：健康人所携带的白喉杆菌的生物学特性不同于标准的有毒力的菌株。