Oxidative damage on DNA induced by asbestos and man-made fibers in vitro

Summary We compared the potential of asbestos and man-made fibers to attack DNA by the determination of the yield of 8-hydroxy-2-deoxyguanosine (8-OH-dGuo) under several in vitro conditions. Asbestos induced 6.6–99.8 of 8-OH-dGuo per 10⁵ dGuo in calf thymus DNA after 20 h of incubation, while the levels of 8-OH-dGuo in man-made fibers were low (3.6–9.4). The amounts of 8-OH-dGuo were strongly stimulated by the addition of H₂O₂ in asbestos, but not in man-made fibers. However, the yield of 8-OH-dGuo was induced more than that with asbestos by the further addition of FeSO₄ in attapulgite, fiberglass, potassium titanate whisker, and metaphosphate polymer. The addition of ethylene diamine tetraacetic acid (EDTA) promoted the induction of 8-OH-dGuo with asbestos and H₂O₂. The effects of mannitol (known as a hydroxy radical scavenger) were not dramatic on 8-OH-dGuo induction by all fibers except fiberglass and basic magnesium sulfate whisker, which induced higher amounts after mannitol addition than in these fibers and H₂O₂. Therefore, it was suggested that asbestos could damage DNA, resulting in 8-OH-dGuo as a cause of point mutation, and also several types of manmade fibers had similar effects to asbestos under certain conditions.     

Trans-3′-hydroxycotinine as a main metabolite in urine of smokers

Summary Nine mal smokers smoked three types of cigarettes that differed in mainstream nicotine. The experiment was carried out in three runs, each consisting of 7 d when smoking was allowed and 5 d when it was not allowed. Urine fractions were collected throughout the whole period of the experiments. As assumed, nicotine and four of its known metabolites, i.e., cotinine, nicotine-N-oxide, nornicotine, and N-methyl-nicotinum ions were found in the urine. In addition, trans-3- hydroxycotinine was determined. The amount of this metabolite was well in excess of those of nicotine and cotinine in the urine. The serum concentration trans-3-hydroxycotinine was found to be second to serum cotinine.     

Excretion kinetics of the rubber anti-oxidant N-isopropyl-N′-phenyl-p-phenylendiamine (IPPD)

Summary Sixteen rubber vulcanizers using IPPD as anti-oxidant were monitored for the presence of the parent compound in the urine during two consecutive working weeks using HPLC for analysis. At least two components in the excretion kinetics could be demonstrated: a fast one, as end-shift urinary concentrations significantly exceeded before-shift ones, and a less rapid one, as before-shift values at the end of the week significantly differed from those determined at the beginning. A skin absorption experiment was also performed. It demonstrated three components in the excretion kinetics, with apparent half-times of approximately 3, 7 and 24 h. Excretion ceased 7 d after skin exposure.     

4,4′-Methylenedianiline in hydrolysed serum and urine from a worker exposed to thermal degradation products of methylene diphenyl diisocyanate elastomers

A 45-year-old mechanic employed in blowing hot air (350°–600°C) onto the surface of a polyurethane methylene diphenyl diisocyanate (MDI) conveyer belt developed dyspnoea, rhinoconjunctivitis and fever. The illness was suggestive of an MDI-associated illness, compatible with both immediate hypersensitivity and a complement-mediated immune-complex reaction. In his serum there were specific IgG and IgE antibodies against MDI and other isocyanates, and high values of circulating immune complexes. The patient's blood and urine samples were analysed for the presence of 4,4-methylenedianiline (MDA) in hydrolysed urine and plasma. MDA was derivatized to amides using pentafluoropropionic acid anhydride (PFPA). Gas chromatography-mass spectrometry determinations were made monitoring the (M-20; M = molecular mass) fragments from the MDA-PFPA and the [²H₂]MDA-PFPA derivative. The first urine sample was obtained 22 h and the last sample 114 h after start of exposure. The urine concentrations of MDA were corrected for creatinine. The half-time of MDA was 70–80 h. The first serum sample was obtained 19 h and the last sample 1967 days after the start of exposure. The half-time was 21 days, which suggests the presence of MDI/MDA plasma protein adducts in the exposed worker.     

Determination of urinary 4,4′-methylenedianiline and its acetylated metabolites by solid-phase extraction and HPLC analysis with UV and electrochemical detection

An analytical procedure based on solid-phase extraction and high-performance liquid chromatography using both ultraviolet and electrochemical detection was developed to determine, without derivatization, stable urinary forms of 4,4-methylenedianiline (MDA) and of its acetylated metabolites at the pg/1 level, in post-shift urine from 63 exposed workers. The determination of MDA,N-acetyl MDA (MAMDA) andN,N-diacetyl MDA (DAMDA) was achieved on the non-hydrolysed urine samples, and that of total MDA on urine samples after alkaline hydrolysis. It was necessary to protect urine samples with sulfamic acid in order to stabilize amines and to improve the precision and accuracy of the analyses. Under these conditions, unstable labile conjugates were determined as their parent stable amine. The distribution of total MDA, MDA, MAMDA and DAMDA was assessed in 116 urine samples. Their relative concentrations (arithmetic means) were found to be in the following order: total MDA > MAMDA > MDA > DAMDA. While MAMDA represented more than 50% of total MDA, MDA and DAMDA were lower than 15% and 3% respectively. Acetylation of MDA, described as a possible pathway of detoxication, is confirmed to be an important metabolization route in humans, essentially through the monoacetylated metabolite. However, the individual ratio MAMDA/total MDA was found to vary widely (roughly from 0% to 100%).     

Studies on erythrocyte pyrimidine 5′-nucleotidase (P5N) test and its evaluation in workers occupationally exposed to lead

Summary An erythrocyte pyrimidine 5-nucleotidase (P5N) test was performed for 171 workers occupationally exposed to lead. Erythrocyte P5N activity was markedly inhibited by exposure to lead. Among several biological indicators (erythrocyte P5N, -aminolevulinic acid dehydratase (ALAD), protoporphyrin (PROTO), urinary -aminolevulinic acid (ALA), coproporphyrin (COPRO)), the P5N activity had the highest correlation with the concentration of lead in blood (r = – 0.77). A significant inhibition of erythrocyte P5N was found in groups of lead workers with blood-lead levels of more than 10 to 19 g/dl. This P5N inhibition started before any changes occurred in urinary ALA and COPRO. A 45 to 50% inhibition of P5N corresponded to the blood-lead value (50 g/dl) of the BEI recommended by ACGIH. In some lead workers, erythrocyte nucleotides (mainly CTP and UTP) were determined. The data indicated that a marked accumulation of these nucleotides had occurred, and their levels correlated negatively with P5N activity and positively with blood lead.     

Biomonitoring of 4,4′-methylene dianiline by measurement in hydrolysed urine and plasma after epicutaneous exposure in humans

Five healthy volunteers were dermally exposed for 1 h to 0.75–2.25 mol 4,4-methylene dianiline (MDA) dissolved in isopropanol, by use of a patchtest technique. Determination of MDA remaining in the patch units after exposure showed that a median of 28% (range 25–29%) was absorbed. By analysis of hydrolysed plasma, an initial accumulation of MDA could be shown, and then a decline. MDA was also detected in hydrolysed urine. The maximum rate of MDA excretion in urine was found 6–11 h after the onset of exposure. Within two subjects studied at three doses, the urinary excretion was proportional to the exposure. The elimination half-lives (elim-t _1/2) in plasma and urine had medians of 13 and 7 h, respectively. In eight out of nine exposures, the elim-t _1/2 was longer in plasma than in urine. Slow acetylation seemed to be associated with short elim-t _1/2 in urine. The median of total MDA amount excreted in urine during 48 h, was 33 nmol for the five subjects exposed to 0.75 mol, which corresponded to roughly 16% (range 2%–26%) of the absorbed dose while only a limited number of individuals were studied, the data still indicated that MDA in hydrolysed plasma or urine can be used for biological monitoring of occupational dermal exposure. However, the individual variation must be taken into account. Sampling should preferably be made several hours post shift. Urine is preferred before plasma at low exposures, because of its higher concentrations of MDA.     

The relationship between zinc protoporphyrin (ZPP) and “free” erythrocyte protoporphyrin (FEP) in lead-exposed individuals

Summary The relationship between zinc protoporphyrin (ZPP) and total erythrocyte protoporphyrin, measured as free erythrocyte protoporphyrin (FEP), was determined in 194 adult subjects with different occupational and non-occupational lead exposures. Furthermore, the ZPP-FEP comparison was considered with respect to the dose-effect relationship of ZPP and FEP with blood lead (PbB) for males and females, respectively. Bilirubin (Bil.) interferences in ZPP analysis were taken into account. A very close and highly significant relationship (r=0.962, P<0.001) was established between ZPP and FEP values. A significant correlation (P<0.001) between log ZPP or log FEP and PbB (malesr=0.767 and 0.718; femalesr=0.525 and 0.405) was also found. It was established, by both in vitro and in vivo studies, that Bil. interferes with the ZPP fluorescence readings; the relationship between false positive ZPP concentrations and Bil. concentrations (in vitror=0.987, in vivor=0.903) was highly significant (P<0.001). A small but highly significant (r=0.948,P<0.001) influence of increased carboxyhemoglobin (COHb) concentrations on the decrease in hematofluorometer ZPP readings, due to inadequate oxygenation of the blood, was found. The results obtained confirm the usefulness of ZPP determinations using hematofluorometers for surveillance of increased lead absorption but stress that the interfering effect of Bil., and to a lesser extent of COW cannot be ignored.The authors, who share equal responsibility for this paper, have been placed in alphabetical order     

Relationship between inhibition of erythrocyte pyrimidine 5′-nucleotidase activity and biological response for porphyrin metabolism in workers occupationally exposed to lead

Summary A rapid determination of erythrocyte pyrimidine 5-nucleotidase (P5N) activity in lead workers was carried out using a high-performance liquid chromatograph (HPLC). The P5N activity had a good negative correlation with the concentration of lead in blood (PbB) ranging from 16 to 96 g/dl (r = -0.82, n = 77). Further, the P5N was compared with other biological parameters: erythrocyte -aminolevulinic acid dehydratase (ALAD) activity, erythrocyte protoporphyrin (PROTO), urinary -aminolevulinic acid (ALA) and urinary coproporphyrin (COPRO).The correlation coefficients between P5N and ALAD, log PROTO, log ALA, and log COPRO were 0.59, –0.72, –0.65, and –0.61, respectively. On the other hand, the normal value of P5N obtained from 72 healthy subjects was 11.9 ± 2.1 units; ol uridine/h/g Hb (mean ± SD), indicating that the lower limit of 95% confidence interval for normal P5N was about 8 units. When P5N was cut off at 8 units in 77 lead workers, the validity (sensitivity + specificity) for PbB 40 g/dl, PbB 60 gg/dl, erythrocyte PROTO 150 g/dl RBC, urinary ALA 6 mg/l, and urinary COPRO 150 g/l was 1.66, 1.76, 1.57, 1.68, and 1.60, respectively. From these results, it was confirmed that the erythrocyte P5N test is suitable for the biological monitoring of exposure to lead in a wide range, and its activity is useful in predicting the disturbance of porphyrin metabolism induced by lead.     

Mutagenicity of 4,4′-methylene-bis-(2-chloroaniline) “MOCA” and its N-acetyl derivatives in S. typhimurium

Summary 4,4-methylene-bis-(2-chloroaniline) (MOCA) and two identified urinary N-acetyl and N,N-diacetyl derivatives were tested in a Salmonella/mammalian microsome assay. No mutagenic activity was observed without rat liver S9 mix activation. In the presence of rat liver S9 mix, the chemicals were mutagens, but the mutagenicity of N-acetyl derivatives to strain TA 100 was reduced when compared to that of MOCA, and a greater amount of S9 was required to exhibit the mutagenicity of the N,N-diacetyl-MOCA. These data suggest that N-acetylation does not account for the mutagenic effectiveness of MOCA.     

Vitamin E serum levels in patients with leukemia, lymphoma and myeloma

The serum -tocopherol levels were determined in a group of 182 patients with hematological neoplasms: 87 lymphoid or myeloid leukemias, 65 lymphomas and 30 myelomas. The levels did not differ from those of controls, when compared either globally or for diagnosis. Low -tocopherol serum levels were observed in 6 patients (3.3%).     

The Epping Jaundice outbreak: mortality after 38 years of follow-up

Objective: To investigate mortality in individuals exposed to 4,4-methylenedianiline (MDA). Methods: The mortality of 84 individuals, accidentally poisoned with MDA during the Epping Jaundice outbreak of 1965, was compared with expected values based on national rates defined by age, period and sex, for the period 1965–2002. In addition, cancer registration data were analysed for the period 1971–2002. Results: The vital status of 83% of the group was established, with 37 deaths occurring before the end of follow-up. Mortality from all causes was close to expectation among females (Obs, 25; Exp, 30.3; SMR, 82), and below expectation among males (Obs, 12; Exp, 26.7; SMR, 45). There were no observed deaths from cancer of the liver or from nonmalignant liver disease. Conclusions: This study has found no evidence to suggest that the ingestion of MDA had adversely affected mortality.     

Usefulness of the SF-8™ Health Survey for comparing the impact of migraine and other conditions

Background: Migraine headaches have been shown to have substantial personal and societal implications. Health-related quality of life (HRQOL) assessments of migraineurs have been used to monitor and evaluate patient- and population-based outcomes, and to evaluate effectiveness and responsiveness to treatment. In this paper, we test a new, even shorter generic health survey, the SF-8 Health Survey (SF-8), an alternate form that uses one question to measure each of the eight SF-36^® Health Survey (SF-36^®) domains, in a sub-sample of migraine sufferers. Methods: Data from 7557 participants surveyed via the Internet and mail were used to document the burden of migraine on HRQOL and to compare the relative burden of migraine with other chronic conditions using the SF-8. Results: Migraineurs' HRQOL is similar to those with congestive heart failure, hypertension and diabetes, and is better than those with depression. Migraine sufferers experience better physical health and worse mental health (MH) than those with osteoarthritis. Results support prior research indicating that the burden of migraine on functional health and well-being is considerable and comparable to other chronic conditions known to have substantial impact on HRQOL. Conclusions: The SF-8 may provide a more practical and efficient method to describe the burden of migraine in population studies.     

Serum hexachlorocyclohexane residues in workers engaged at a HCH manufacturing plant

Summary The accumulation of hexachlorocyclohexane, one of the most commonly used chlorinated insecticides, was studied in a high-risk group of people who are exposed during its manufacturing process. The serum HCH concentration was estimated by quantitating its , , and -isomers with the help of GLC analysis. Exposed workers involved in maintenance work were found to have 3 times higher HCH residues than the controls, while in the plant operators and supervisors the levels were 5 times higher. The most severely exposed were the handlers who are in direct contact with the insecticide. The level of serum HCH residues in them was found to be about 12 times higher than those in the controls. The percentage composition of the insecticide, with respect to the different isomers, varied up to 20% for the -isomer, up to 30% for -isomer and had between 60%–100% of the -isomer in the samples. The serum levels of the insecticides were clearly related to the workers' job-related close contact, intensity, frequency, and the duration of their exposure. The total of HCH residues in the sera studied were in the range of 0.143–1.152 ppm. The importance of these findings and the relevant protective measures are discussed.     

Influence of smoking on aminolevulinic acid dehydratase activity,haematocrite and lead in blood in adult urban women

Summary In adult urban women the effect of smoking 10 or more cigarettes per day on Ht, ALA-D activity and PbB-level was studied. Within the range of PbB-levels studied (up to 240 ppb in whole blood) smoking increased hematocrite, and so the transport capacity of total peripheral blood for Pb and the total ALA-D activity. Decrease of ALA-D-activity per cell volume was for 20 % due to increased PbB-level per cell volume as related to smoking, and for 80 % due to a direct effect of smoking. If one wants to study whether a no-effect level of PbB on ALA-D exists, one has to examine non-smokers.     

Renal elimination of verbenols in man following experimental α-pinene inhalation exposure

Summary The renal elimination of verbenols after experimental exposure to (+) and (–)-pinene was studied in humans following exposure to 10, 225, and 450 mg · m^–3 terpene in an exposure chamber. The pulmonary uptake was about 60%. About 8% was eliminated unchanged in exhaled air. Depending on the exposure level, about 1%–4% of the total uptake was eliminated as cis and trans-verbenol. Most of the verbenols were eliminated within 20 h after a 2-h exposure. The renal excretion of unchanged -pinene was less than 0.001%.     

Occurrence of plasmids in “Campylobacter upsaliensis” (catalase negative or weak group) from geographically diverse patients with gastroenteritis or bacteraemia

The natural occurrence of plasmids in Campylobacter upsaliensis (catalase negative or weak campylobacters: CNW group) was investigated. The 62 strains isolated from patients with gastroenteritis or bacteraemia in five countries (South Africa, Belgium, Sweden, UK and Australia) were screened for plasmid DNA, which was detected in 54 (87%) of them. Plasmids were of various sizes between 1.4 and 90-Md and up to three or possibly four plasmids were present in 26 (42%) strains. A total of 15 different plasmid profile types were identified. Strains of profile type 2, containing 2.8-, 34- and 60-Md plasmids and a less distinct 5-Md plasmid, were the most frequently encountered (22 strains) and they exhibited a wide geograhical distribution. Overall the 34- and 2.8-Md plasmids were the commonest occurring in 58 and 55% of plasmid containing strains respectively. Nine strains from dog faeces were also examined and some had identical profiles to human isolates, suggesting a possible animal to man transmission route. These findings show that plasmid profiling has considerable potential as a typing method for C. upsaliensis.     

Blood toluene as a biological index of environmental toluene exposure in the “normal” population and in occupationally exposed workers immediately after exposure and 16 hours later

Blood toluene was measured in a group of 100 workers occupationally exposed to a mean 8-h environmental toluene concentration of 128 g/l (34 ppm), and in a group of 269 normal subjects without occupational exposure to toluene. The mean blood toluene of the workers at the end of the shift and the following morning, after 16 h, was 457 and 38 g/l, respectively. The normal subjects had a blood toluene level of 1.1 g/l. On the basis of the highly significant correlation between blood toluene and occupational exposure, it can be calculated that environmental toluene exposure of 188 and 377 g/l (50 and 100 ppm) gives end-of-shift blood toluene levels of 690 and 1390 g/l, respectively. The corresponding blood toluene levels on the following morning are 50 and 100 /l, respectively.     

Untersuchungen zur beziehung zwischen vinylchlorid (VCM)-aufnahme und metabolitenausscheidung bei 15 VCM-exponierten

Summary Fifteen workers employed in a PVC producing plant were investigated concerning their individual vinyl chloride (VCM) exposure and the urinary excretion of the VCM metabolite thiodiglycolic acid (TdGA). The urine concentrations found were in the range 0.94–20.4 g/ml. These could be compared with exposure data calculated from VCM air analyses performed by personal air sampling and corrected with respect to the exposure times of the workers. The amounts of TdGA excreted within 24 h were correlated with the effective VCM body concentrations calculated from the exposure data as mean values for 12 h periods (Spearman coefficient P=<0.005). This correlation resembles a function of the Michaelis-Menten type. It could be shown that during short exposure periods of less than 5 min, the metabolite formation in relation to the exposure data was lower than during longer periods of exposure although, as would be expected, there were some fluctuations of the exposure level. Therefore, the VCM body concentrations could not normally reach steady state values.

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Untersuchungen zur beziehung zwischen vinylchlorid (VCM)-aufnahme und metabolitenausscheidung bei 15 VCM-exponiertenII. Messungen zur ausscheidung des VCM-metaboliten thiodiglykolsaure im harn

Zusammenfassung In einer Feldstudie an 15 Beschäftigten eines PVC-produzierenden Betriebes wurde der Zusammenhang zwischen der Höhe der Exposition gegenüber monomerem Vinylchlorid (VCM) und der Ausscheidung des VCM-Harnmetaboliten Thiodiglykolsäure (TdGA) untersucht. Die ermittelten Harnkonzentrationen, die sich zwischen 0,94 und 20,4 g/ml bewegten, konnten mit Expositionsdaten verglichen werden, die durch personal air sampling unter Berücksichtigung der Aufenthaltszeiten im Expositionsbereich gewonnen werden waren.Aus den mit Personendosimetern gewonnenen Analysedaten wurden unter Berücksichtigung pharmakokinetischer Gesetzmäßigkeiten die effektiven VCM-Körperkonzentrationen als 12-h-Mittelwerte kalkuliert. Mit diesen waren die im 24-h-Harn ausgeschiedenen Mengen an TdGA deutlich korreliert (P=<0,005; Spearman-Koeffizient). Die Korrelation entspricht in guter Näherung einer Funktion vom Michaelis-Mengen-Typ. Unter Berücksichtigung der Arbeitsprotokolle konnte aus den Meßdaten abgeleitet werden, daß bei Ansteigen der VCM-Luftkonzentration für Zeiträume von weniger als 5 min die Metabolitenausscheidung relativ zur kalkulierten mittleren Körper-konzentration geringer ansteigt als bei längerfristigen Expositions schwankungen. Offenbar schwankte die VCM-Raumluftkonzentration derart, daß die VCM-Körperkonzentrationen den Gleichgewichtswert in der Regel nicht erreichten.

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Abkürzungen VCM Vinylchlorid Monomer - TdGA Thiodiglykolsäure - p.a.s. personal air sampling Mit Unterstützung der Berufsgenossenschaft der Chemischen Industrie     

Validation of general practitioner-diagnosed COPD in the UK General Practice Research Database

Background: Information in large, automated databases can be useful to study the natural history of respiratory diseases in the community, but the validity of definitions needs to be demonstrated. Aim: To compare a simple computer algorithm that identifies patients diagnosed with chronic obstructive pulmonary disease (COPD) and severity of COPD in the UK General Practice Research Database (GPRD) with general practitioner (GP) clinical records, to evaluate the utility of this algorithm for identifying COPD patients and for distinguishing COPD from asthma. Methods: Using a computer algorithm identifying patients by diagnostic codes and allotting three grades of severity by drug use, a sample of 225 patients in the GPRD with a diagnosis of COPD and an age–sex matched group of 75 patients with asthma were randomly selected. Questionnaires were posted to the GPs of the 300 selected patients who were asked to state diagnosis and to grade severity based on the individual's medical record. Agreement was quantified with the index, an estimator that accounts for agreement that occurs by chance. Results: Response rate was 85.7%. The concordance between COPD diagnosis by the GPRD algorithm with that of the GP was quantified as a of 0.52, and the concordance between COPD severity by the GPRD algorithm with that of the GP was quantified as a of 0.54. The index for COPD diagnosis increased with increasing severity of COPD (0.46, 0.59, and 0.68 for mild, moderate and severe COPD, respectively), but similar good agreement was observed in a stratified analysis by sex, age, smoking status and number of comorbidities. Conclusions: It is concluded that the GPRD algorithms used for diagnosis and severity of COPD are a good screening tool for COPD in the UK general population, and satisfactorily differentiate COPD from asthma patients, particularly when disease is moderate or severe.