Healthconditions were evaluated in 80electrical workers exposed for many years to polychlorinated biphenyl (PCB) mixtures with a 42% mean chlorine content, who had blood PCB concentrations from 41 to 1319 pg/kg. The clinical study was based on personal history data, physical examination, and laboratory tests (red cell and leukocyte count; determination of haemoglobin, packed cell volume, bilirubin, serum protein electrophoretic fractions, pseudocholinesterase, AST, ALT, GGT, and OCT). Fifteen workers were found to have skin diseases-chloracne (4), folliculitis (4), oil dermatitis (1), juvenile acne (1), and dermatitis due to irritative or allergic agents (5). Sixteen workers showed more or less pronounced hepatic involvement, consisting most often of hepatomegaly with an increase in serum GGT, AST, ALT, and OCT values. In two workers bleeding cavernous haemangiomas were discovered, in one case associated with chronic myelocytic leukaemia. All the workers with chloracne were employed on electric capacitor impregnation with PCBs, and no definite association was found between chloracne and blood PCB concentrations. Conversely, a significant positive association was found between the abnormal liver findings and blood PCB concentrations, particularly trichlorobiphenyl blood concentrations.The abnormal hepatic findings observed are similar to those reported in experimental animals given PCBs, and in some workers such findings should probably be considered as clinical signs of hepatic microsomal enzyme induction.The toxicity of polychlorinated biphenyls (PCBs) has been studied in several animal species: high oral doses of PCBs induce liver damage in non-human primates and in rodents.1-4 In monkeys, depending on dose and mode of administration, acne, alopaecia, hyperpigmentation of the skin, thymic atrophy, ocular lesions, and subcutaneous oedema have been also observed.5-7 In rodents, however, low doses of PCBs, not sufficient to cause macroscopically evident organic disease, can alter several biochemical functions: after chronic oral or parenteral PCB administration it was possible to show an increase in the smooth endoplasmic reticulum of liver cells with induction of microsomal enzyme activity,8-'0 hepatic porphyria, Requests for reprints to:

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A contact investigation following a case of infectious tuberculosis (TB) reported in a call centre in Milan (Italy) led to the identification of three additional cases that had occurred in employees of the same workplace during the previous 5 years, one of whom was the probable source case. Thirty-three latent infections were also identified. At the time of diagnosis, the source case, because of fear of stigma related to TB, claimed to be unemployed and a contact investigation was not performed in the workplace. Cases were linked through genotyping of Mycobacterium tuberculosis. TB stigma has been described frequently, mainly in high-incidence settings, and is known to influence health-seeking behaviours and treatment adherence. The findings in this report highlight that TB-associated stigma may also lead to incomplete contact investigations. Little is known about the causes and impact of TB-related stigma in low-incidence countries and this warrants further exploration. Research is also needed to evaluate the effectiveness of specific interviewing techniques and training interventions for staff in reducing feelings of stigma in TB patients. Finally, the outbreak emphasizes the importance of integrating routine contact investigations with genotyping.

Industrial exposure to polychlorinated biphenyls (PCBs) and internal dose were investigated in 80 workers exposed for many years to PCB mixtures with a 42 % chlorine content (Pyralene 3010 and Apirolio). PCBs were determined by liquid gas chromatography on samples taken from workroom air, workroom surfaces and tools, the palms of the hand, and the blood of the workers.In the workroom air samples, PCB concentrations ranged from 48 to 275 ttg/m3. All tested surfaces and tools were heavily contaminated, with a range from 0-2 to 159 ,ug PCBs per cm2 of surface. Considerable amounts of PCBs were detected on the palms of the hands of the workers (2-28 ,ug/cm2 of skin surface). In blood, total PCB concentrations from 88 to 1319 ,ug/kg were observed: comparing the blood concentrations of low and high chlorine content biphenyls, a significant difference was found for the low-chlorinated biphenyl concentrations between workers currently exposed and workers exposed only in the past.

The aim of this study was to investigate the capability of Gd-DTPA-enhanced MRI to differentiate between exudative and transudative pleural effusions. An MRI examination was performed on 22 patients with different types of pleural effusion (10 transudative and 12 exudative effusions). T1-weighted SE images were obtained before and 20 min after administration of Gd-DTPA (0.1 mmol/kg). The degree of enhancement of pleural effusions was evaluated both by visual assessment and by quantitative analysis of images. None of 10 transudative effusions showed significative enhancement, whereas 10 of 12 exudative effusions showed enhancement (sensitivity 83 %, specificity 100 %, positive predictive value 100 %). The postcontrast signal intensity ratios (SIRs) of exudates were significantly higher than corresponding precontrast ratios (P = 0. 0109) and the postcontrast SIRs of exudates were significantly higher than those of transudates (P = 0.0300). Exudative pleural effusions show a significant enhancement following administration of Gd-DTPA. We presume that this may be caused by increased pleural permeability and more rapid passage of a large amount of Gd-DTPA from the blood into the pleural fluid in case of exudative effusions. In our limited group of patients, signal enhancement proved the presence of an exudative effusion. Absence of signal enhancement suggests a transudate, but does not exclude an exudate.