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Biomedical subjects

M Berode

Publications and source records attributed to M Berode.

At least 37 records · Page 2Linked to original sources
PubMed1991

Detoxification of an aliphatic amine by N-acetylation: experimental and clinical studies.

Incubation of serum serpin (alpha-1-antitrypsin) with 5 mM 1,6-diaminohexane causes significant loss of heterozygotic inhibitor activity. While serpin genes have several alleles, the enzyme complex that acetylates the amine to render it suitable for excretion has primarily two phenotype populations, i.e. slow and fast N-acetylators. This study shows that diacetyl-1,6-diaminohexane does not cause in vitro loss of serpin activity, and that all regional cases (eleven in all) referred to us during one year with a diagnosis of occupational organic diisocyanate asthma were slow acetylators except one who presented a marginally fast reaction type.

Acetylation↗
PubMed1990

Hydrocarbon exposure, hypertension and kidney function tests.

Control and hydrocarbon exposed workers participated in a cross-sectional study about the nephrotoxicity of chronic hydrocarbon exposure. Different markers of glomerular and tubular function as well as the celluria were examined and compared. The results show that the interaction between hypertension and hydrocarbon exposure has an influence on the kidney function. For the clearance the interaction age-exposure seems to play a more important role than age or exposure alone. The most useful markers appear to be the albuminuria, the N-acetyl-beta-D-glucosaminidase activity, the retinol-binding-protein concentration and the creatinine clearance.

Adult↗
PubMed1990

Demethylation pathways in caffeine metabolism as indicators of variability in 1,1,1-trichloroethane oxidation in man.

Twenty volunteers were exposed to 191 +/- 7 p.p.m. 1,1,1-trichloroethane or 50 +/- 2 p.p.m. perchloroethylene vapour for 6 hr. They were then evaluated for their rate of caffeine metabolism, mephenytoin hydroxylation and debrisoquine hydroxylation. Seven subjects were identified as 'fast acetylators' of caffeine and one person as a slow metabolizer of debrisoquine. The "slow acetylators" exposed to perchloroethylene excreted an average of 3.83 +/- 0.35 mg trichloroacetic acid within 24 hr (N = 13, +/- S.E.) and the 'fast acetylators' 3.58 +/- 0.48 mg (N = 7, +/- S.E.). The excretion of trichloroethanol by the same persons after 1,1,1-trichloroethane exposure was 14.1 +/- 1.12 mg and 16.7 +/- 1.48 mg, respectively. The excretion of trichloroacetic acid in the latter exposure varied significantly between the seven 'fast' and 13 'slow acetylators' (0.43 +/- 0.08 mg versus 1.03 +/- 0.19 mg; +/- S.E.; P = 0.037). A multiple linear regression analysis confirmed this association when other factors, such as body weight, creatinine clearance, smoking habit and alcohol consumption, were taken into account. One volunteer proved to be a poor hydroxylator of debrisoquine and excreted half the amount of trichloroacetic acid in the perchloroethylene exposure and half the amount of trichloroethanol in the 1,1,1-trichloroethane exposure compared to the others. A reduction in the solvent metabolism could thus be predicted by the debrisoquine test. On the other hand, the caffeine test predicted faster oxidation of trichloroethanol which could be of toxicological and pharmacological importance e.g. in the clinical use of chloral.

Adult↗
PubMed1989

Variability in biological monitoring of solvent exposure. I. Development of a population physiological model.

Biological indicators of exposure to solvents are often characterised by a high variability that may be due either to fluctuations in exposure or individual differences in the workers. To describe and understand this variability better a physiological model for differing workers under variable industrial environments has been developed. Standard statistical distributions are used to simulate variability in exposure concentration, physical workload, body build, liver function, and renal clearance. For groups of workers exposed daily, the model calculates air monitoring indicators and biological monitoring results (expired air, blood, and urine). The results obtained are discussed and compared with measured data, both physiological (body build, cardiac output, alveolar ventilation) and toxicokinetic for six solvents: 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, benzene, toluene, styrene, and their main metabolites. Possible applications of this population physiological model are presented.

Adipose Tissue↗
PubMed1988

Biological monitoring of styrene: a review.

Recent literature about the biological monitoring of styrene-exposed workers is reviewed. Styrene primarily exhibits its toxicity on the central and peripheral nervous systems, although its mutagenicity and chromosome damaging ability also may be relevant. Uptake, transformation and excretion of styrene show that beside the usual biological indicators, such as urinary mandelic and phenylglyoxylic acids (main metabolites), other indicators also may be of interest. These include styrene in expired air, in blood or in urine. Moreover, intermediate or final metabolites such as styrene glycol or mandelic acid in blood also have been proven to be useful in the interpretation of individual values. The most widely used analytical methods for these indicators are gas or high performance liquid chromatography. Correlations between exposure and the different biological indicators mentioned above show that the most reliable indicators are mandelic acid (MA) in urine sampled at the end of the work shift (but not the first day of the week) and the sum of mandelic and phenylglyoxylic acids (MA + PGA) in urine sampled 16 hr after exposure (before the next shift). The biological exposure limit values corresponding to the threshold limit value-time-weighted average (TLV-TWA) of 50 ppm of styrene are 850 mg MA/g creatinine in the end-of-shift sample and 330 mg MA + PGA/g creatinine in the next-morning sample. Other biological indexes, such as styrene glycol (phenyl ethylene glycol) in blood or styrene in urine, look promising but require further research in field situations.

Absorption↗
PubMed1988

Human leucocyte elastase and serum alpha 1-antitrypsin.

Human leucocyte elastase concentration and its major circulating inhibitor, the alpha 1-antitrypsin, were compared in blood samples taken from 17 healthy male donors. Leucocyte elastase concentration was linearly correlated to the serum antitrypsin activity determined by its phenotypic constitution. Thus it seems that cellular elastase and its circulating inhibitor activities are closely coregulated. This might be mediated by the leucocyte elastase receptors which internalize free elastase possibly suppressing synthesis of the enzyme.

Adult↗
PubMed1988

Phenotype-dependent inhibition of human alpha 1-antitrypsin by 1,6-hexane diamine in vitro.

Blood donors and patients from pulmonary wards gave serum specimens for the assay of their alpha 1-antitrypsin activity and phenotype. The same specimens were then incubated at the room temperature overnight with increasing concentrations of 1,6-hexane diamine. The 5 mM amine concentration caused a significant decrease in heterozygous antitrypsins (M1M2, M1M3, M2M3 and M1S) activity while it was less in the homozygous (M1M1 and M2M2) antitrypsin phenotypes. The SS and ZZ phenotypes showed a very low initial activity which was, however, further reduced. Analysis for the antitrypsin protein showed a simultaneous loss of its activity. The data suggest that heterozygous antitrypsin carriers may be more prone to the effects of inhaled amines despite their 'normal' phenotypic constitution.

Diamines↗
PubMed1986

[Monitoring of persons exposed to perchloroethylene or styrene].

Forty-nine employees exposed to perchloroethylene (dry cleaning) and 41 employees exposed to styrene (fiber reinforced polyester) are compared to a control group of 68 persons. Symptoms such as dizziness, mouth dryness, fatigue, mucous membranes and skin irritation appear more frequently among the exposed groups, while liver and kidney functions remain unchanged. This study demonstrates that medical examination, industrial hygiene survey and biological monitoring can complement each other in the evaluation of work conditions.

Adult↗
PubMed1986

[Preventive examinations in the rotogravure printing industry].

One hundred and sixty rotogravure printing workers exposed mainly to toluene are compared (clinical examination, liver and kidney tests) to 38 unexposed workers. The exposure to toluene is assessed by personal air sampling at the workplace (mean: 54 ppm) and by analysis of hippuric acid in urine (mean: 1.86 g/g creatinine). Fatigue, alcohol intolerance, mouth dryness appear more frequently among the exposed subjects. Differences observed in liver tests are difficult to relate to toluene exposure. The additional eight-year health surveillance of 18 workers shows no significant changes in liver and kidney functions.

Adult↗
PubMed1985

Human exposure to styrene. VI. Percutaneous absorption in human volunteers.

In order to estimate the importance of skin resorption of styrene, as compared to pulmonary absorption, nine male volunteers were exposed for 10 to 30 min by dipping one hand in liquid styrene. Urine and breath were sampled periodically for metabolites (mandelic and phenylglyoxylic acids) and styrene analyses respectively. The results obtained show that the rate of absorption of styrene through the skin is very low, averaging 1 +/- 0.5 micrograms/cm2 X min. This rate seems to be affected by the duration of exposure. In conclusion, this study shows that skin resorption plays only a minor role in most practical situations.

Adult↗
PubMed1983

Measurement of hand tremor induced by industrial exposure to metallic mercury.

Hand tremor due to industrial exposure to metallic mercury vapour was recorded in 26 exposed and 25 non-exposed male workers by an accelerometer attached to the dorsum of the hand. The subjects were instructed to hold the hand and the forearm in the same position first without and then with a load of 1250 g supported by the hand. Analysis of the records showed that the highest peak frequencies (HPF) (the frequency corresponding to the highest acceleration) were higher in the exposed men than in the controls and were related to the duration of exposure to mercury and to age. The changes in HPF between rest and load were again higher in the exposed men than in the controls and again related to the duration of exposure and to age. The second moment (M2) (an index taking into account the whole recorded spectrum) was similar in the exposed men and controls at rest. The changes in M2 between rest and load were higher in the exposed men than in the controls but were related to duration of exposure and to the biological measurements (loge of mercury in urine or blood) and not to age. These neurophysiological impairments might result from the tendency of metallic mercury to accumulate in the cerebellum and the basal ganglia. These results are consistent with the hypothesis that metallic mercury, even at concentrations probably below the current TLV-TWA of 0.05 mg/m3, can lead to neurological disorders.

Adult↗
PubMed1982

[Wine growers and pesticides].

Thirty wine growers have been examined in a preliminary study to define the morbidity related to the use of pesticides. The health status was defined (history, physical examination, liver and kidney function study, cholinesterase, EMG) before any exposure and some parameters were reassessed during exposure. Several results vary significantly during treatment with pesticides (ALT, AST, OCT, ACHE, BCHE). The initial health status is good, showing no systematic pathology. Several episodes of acute intoxication are mentioned in the patient's histories.

Adult↗
PubMed1977

[Clinical study and evolution of various biological parameters (Pb, ALA-D, FEP) in 14 cases after ingestion of lead containing beverages].

Clinical and biological evolution is reported in 14 individuals (adults, teenagers, children) who had ingested lead-containing beverages stored in glazed pottery. There are marked differences between adults and children regarding the half lives of lead in blood. Almost two years after the discovery of the risk, abnormal amounts of Pb, ALA-D and FEP remain in the absence of any other clinical disturbance. The hazard of glazed pottery is reemphasized.

Adolescent↗
PubMedDate not supplied

[Mercury levels found in fishermen of Lake Geneva].

This paper presents an evaluation of the mercury levels found in a population eating principally fish coming from the Lake of Geneva. A good correlation exists between the blood mercury level and the amount of fish ingested weekly. Interpretation of the results shows that the threshold of fish comsumption should be about 1.4 kg per week and per person.

Animals↗