Search tips
Search criteria

Results 1-25 (78)

Clipboard (0)
Year of Publication
13.  Urinary hippuric acid concentration after occupational exposure to toluene. 
The results of industrial investigations have shown a correlation between the rate of hippuric acid excretion in a single urine sample collected after daily occupational exposure and the amount of toluene absorbed. The rate of hippuric acid excretion and the average concentration of toluene vapour during exposure time were also related. The quantitative range of the test has been limited to amounts exceeding 425 mg of toluene and concentrations exceeding 69 ppm of toluene in the air because of the physiological presence of hippuric acid in urine. The rate of hippuric acid excretion in urine depends on diuresis and is constant for urinary fractions with diuresis of 30 ml/h. The physiological excretion rate was 20 mg/h with a standard deviation +/- 4.3 mg/h, maximal physiological level 33 mg/h.
PMCID: PMC1008450  PMID: 737140
14.  Blood styrene and urinary metabolites in styrene polymerisation. 
The results of the analysis of blood and urine samples for styrene and its metabolites in 491 workers in a styrene polymerisation plant in the United States are reported. The levels of exposure to styrene were estimated to be less than 10 ppm, but nevertheless styrene and metabolites were detectable in more than 50% of workers in polymerisation jobs, within 4 h of exposure. Workers involved in the manufacture and purification of styrene from ethyl benzene also had detectable blood styrene and urinary metabolites in 83% of recently exposed subjects. The relationship between styrene in blood and in subcutaneous fat and urinary metabolites as pharmacokinetic variables is discussed.
PMCID: PMC1008449  PMID: 737139
15.  The effects of water restriction and water loading on urinary excretion of lead, delta-aminolevulinic acid and coproporphyrin. 
Alterations in daily urinary excretion of lead, delta-aminolevulinic acid (ALA), coproporphyrin, creatinine and total solutes following water restriction and water loading were examined in nine lead workers. Excretion of lead, ALA and total solutes was significantly decreased when urinary volume was reduced, showing that these values are dependent on urinary volume: conversely, excretion of coproporphyrin and creatinine was independent of urinary volume. Excretion of lead and total solutes was also dependent on creatinine excretion. The renal excretory mechanism of lead, ALA and coproporphyrin is discussed in the light of these findings.
PMCID: PMC1008448  PMID: 737138
16.  The effect of acrylamide on human polymorphonuclear neutrophils in vitro. 
Acrylamide (CH2CHCONH2), the vinyl monomer of the industrially useful polymer polyacrylamide, is a recognised neurotoxin. Investigation in our laboratory indicated that, in addition to its neurotoxic effect, acrylamide depressed human polymorphonuclear leucocyte (PMN) chemotaxis in vitro. As genetic or chemical inhibition of PMN phagocytic function frequently pre-disposes patients to repeated bacterila infections, the in vitro effects of acrylamide on several other human PMN functions were studied. Acrylamide in concentrations up to 37.5 mg/ml had no effect on trypan blue uptake. However, bacterial ingestion, killing, and induced chemiluminescence were depressed by pre-treatment with acrylamide (10 mg/ml). It seems unlikely that acrylamide exposure alters host resistance to bacterial infections, because (a) large doses of acrylamide are necessary to interfere with phagocytic functions, (b) acrylamide reacts readily with proteins on many tissue cells and may be made inaccessible or non-toxic to PMN'S and (C) PMNs have a rapid turnover rate in the body and non-functional cells would be rapidly replaced by functional cells.
PMCID: PMC1008447  PMID: 737137
17.  TruCutR needle biopsy in asbestosis and silicosis: correlation of histological changes with radiographic changes and pulmonary function in 41 patients. 
A percutaneous needle biopsy was performed with a TruCut needle on 41 patients with suspected pneumoconiosis. Patients selected for biopsy tended to have brief or unusual dust exposure, as well as questionable radiographic opacities. Sixteen had been exposed to asbestos, 13 to silica and 12 to mixed dust containing quartz, coal, iron, asbestos and talc. All patients in the asbestos group and most in the other two groups had a reduced transfer factor. Most patients in the asbestos group and about 25% of the other patients had restrictive ventilatory impairment. Chest radiographs were assessed according to standard films of the ILO U/C International Classification (International Labour Office, 1972). In 25 patients radiographic opacities were absent or acanty (categories 0--1/1). The dominant radiographic feature of many patients exposed to asbestos was a ground-glass appearance or a bilateral elevation of the diaphragm, or both, features difficult to assess according to the ILO U/C scheme. Most histological changes were those usually seen in pneumoconiosis. However, in only two patients with silicosis were silicotic nodules detected. The specimens of seven patients showed a granulomatous inflammation. The severity of alveolar wall involvement correlated well with the transfer factor value but poorly with radiographic changes. The profusion of radiographic opacities also correlated poorly with functional impairment. As a diagnostic tool the needle biopsy was valuable in asbestosis and slightly less so in mixed-dust fibrosis. The biopsy specimens showed changes compatible with asbestosis in 75% of the suspected cases and in 86% of those in which asbestosis was the final diagnosis. In the mixed-dust group pneumoconiosis was confirmed in 67% and 80%, respectively. In the diagnosis of silicosis an open biopsy is probably more reliable than a percutaneous one, particularly if radiographic changes are minimal. Histological changes in the needle biopsy specimen were compatible with silicosis in only 36% of the suspected cases and in 63% of those in which the final diagnosis was silicosis.
PMCID: PMC1008446  PMID: 737136
18.  Industrial bronchitis. 
For many years there has been much argument whether workers in the dusty trades are prone to chronic bronchitis. In 1966 the Medical Research Council issued a report of a Select Committee which concluded that occupationally induced bronchitis did not play a significant part in the aetiology of airways obstruction in dust-exposed men. Since then epidemiological studies have demonstrated that the prolonged inhalation of dust leads to an increase in prevalence of cough and sputum. Furthermore, new physiological techniques have demonstrated a slight decrement in ventilatory capacity as a result of industrial bronchitis, and which is related to lifetime dust exposure. Unlike bronchitis induced by cigarette smoke, the predominant effect of industrial bronchitis is on large rather than small airways and the condition is not accompanied by emphysema.
PMCID: PMC1008445  PMID: 367424

Results 1-25 (78)