Lead poisoning in precious metals refinery assayers: A failure to notify workers at high risk

Lead poisoning in a precious metals refinery fire assayer and a routine OSHA inspection prompted an investigation of the index facility, a survey of the industry, and efforts to notify assayers of this previously unrecognized hazard. Air and blood samples were obtained at the index facility. Management personnel from all fire assay laboratories in Rhode Island and southern Massachusetts were interviewed. The industry's trade association, OSHA, NIOSH, trade unions, and the media were asked to assist in a nationwide notification effort. Assayers at the index facility had excessive exposures to lead due to an age-old, lead-based assaying method that remains the industry gold standard. Blood lead levels of the three assayers (mean 61.3 μ/dl, range 48–86 μg/dl) were considerably higher than those of 16 other refinery workers (mean 27.4 μg/dl, range 13–49 μg/dl). The industry survey revealed inadequate knowledge of both the lead hazard and the applicability of the OSHA lead standard. Notification efforts failed in large part due to economic obstacles. The notification of workers at high risk of lead exposure and the eradication of occupational lead poisoning will require greater attention to economic forces. © 1994 Wiley-Liss, Inc.     

Successful treatment for squamous cell carcinoma of the female urethra with combined radio- and chemotherapy

We report on two cases of women with locally advanced squamous cell carcinoma of the urethra. Patient 1 also displayed regional lymph node metastasis. Treatment comprised combined radiotherapy to 60 Gy and chemotherapy with 5-fluorouracil and cisplatin. Complete response was obtained in both patients, including the inguinal lymph nodes of Patient 1. Patient 1 experienced recurrent inguinal lymph node metastasis on the contralateral side at 42 months after initial treatment, and the same treatment was performed followed by surgical excision. Both patients remain alive with no evidence of disease, at 12 months after recurrence in Patient 1, and at 27 months after treatment in Patient 2.     

5名电离辐射事故患者外周血T细胞T细胞抗原受体、T细胞分化抗原决定簇－3效应的研究

文中报道了５名事故性急性骨髓型放射病患者照后２．５和３．５年外周血Ｔ淋巴细胞Ｔ细胞受体（ＴＣＲ）基因，ＴＣＲ、Ｔ细胞分化抗原决定簇－３（ＣＤ_３）表达与ＴＣＲ／ＣＤ_３复合物功能的辐射效应．发现５名患者于照后２．５年，２名（５．２Ｇｙ和２．４Ｇｙ，５５岁）于照后３．５年外周血Ｔ细胞应答抗ＣＤ３单抗刺激而增殖的能力尚未完全恢复；经同时用ＩＬ－２和抗ＣＤ_３单抗刺激，增殖能力比单用抗ＣＤ_３单抗刺激有所增强；后２名的外周血ＴＣＲ、ＣＤ_３阳性细胞百分率一直低于正常对照和其他患者；并见一患者出现ＤＮＡ重排杂交带型．本文并从ＴＣＲ／ＣＤ_３在介导Ｔ细胞抗原刺激反应中的作用，电离辐射对ＴＣＲ／ＣＤ_３复合物的影响，后果和意义等方面进行了讨论．     

Phototoxicity due to Cachrys libanotis

After classification and identification of the plant, the alcoholic extract of Cachrys libanotis L. was analysed in order to identify the phototoxic agents. The substances responsible for photodermatitis were found to be 4 furocoumarins, of which 3 have been clearly identified, namely 5-methoxy-, 8-methoxy-and 5,8-dmiethoxypsoralen. The structure of a 4th compound was not completely defined.     

The bactericidal activity of pulsed Nd-YAG laser radiation in vitro

Pulsed Nd-YAG laser irradiation of bacteria has been suggested as a possible means of treating contaminated intra-oral sites although relatively few studies have been conducted. In this investigation, the antimicrobial activity of a pulsed Nd-YAG laser was assessed in vitro for a range of oral bacteria using several pulse energies and exposure durations. Pure cultures of each organism were lased in saline suspensions followed by standard colony counting techniques for test and control samples. Microbial inhibition was found to be organism-dependent and varied with energy dose and pulse energy. For all nine test species 120-mJ laser pulses proved more efficient than 80-mJ pulses, with 99.9% kills compared with around 90% kills after exposure to 1800 pulses. These killing activity levels compare favourably with those achieved with other lasers in vitro.     

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.