Correlation between clinical indicators of lead poisoning and oxidative stress parameters in controls and lead-exposed workers

The present study was undertaken to investigate the involvement of oxidative damage in lead-induced toxicity in humans and to enlighten whether oxidative stress indicators are correlated with the known indices of lead toxicity. For these purposes, selected oxidative stress parameters along with some clinical indices of lead poisoning were determined in blood of battery plant workers and control subjects. Workers had significantly increased erythrocyte malondialdehyde (MDA) levels, catalase and glucose-6-phosphate dehydrogenase (G6PD) activities, and decreased blood glutathione:glutathione disulfide ratio compared to the controls. Increased blood lead concentrations and zinc protoporphyrin (ZPP) levels, and decreased delta-aminolevulinic acid dehydratase (ALAD) activity were used as clinical indices of lead toxicity. Statistically significant correlation between oxidative stress parameters and clinical indices implies that disrupted prooxidant/antioxidant balance might contribute to lead-induced toxicity in erythrocytes. A significant correlation was found between ALAD activity and blood lead levels in human subjects. Similarly significant correlation between ALAD activity and erythrocyte MDA concentrations was shown. Present data indicates that ALAD can serve as a valuable biomarker of oxidative stress in lead-exposed hematological system as well as being a biochemical indicator of lead exposure.     

Inhalation exposure to 1,3-dichloropropene in the Dutch flower-bulb culture. Part I. Environmental monitoring

Respiratory occupational exposure to the Z- and E-isomers of 1,3-dichIoropropene (DCP)² of twelve commercial applicators was assessed. The time-weighted average (TWA) concentrations of DCP ranged from 1.9 to 18.9 mg/m³. On 30% of the observed working days the Dutch occupational exposure limit of 5 mg/m³ was exceeded. Short-term exposure levels during tank-loading and repair were up to 30 mg/m³.Emission of dichloropropene during the injection process has a major impact on the TWA concentration. Modification of the injection system may reduce the concentration of DCP substantially.Abbreviations TWA Time-Weighted Average - OEL Occupational Exposure Limit - Z- and E-DCP Z- and E-isomers of 1,3-dichloropropene - DCP 1,3-dichloropropene     

Pesticides in the cultivation of carnations in greenhouses: Part II--Relationship between foliar residues and exposures.

The relationship between the levels of dermal and respiratory exposure to pesticides and the amount of pesticide on the leaves of the plants has been studied during cutting of carnations in greenhouses. The study was focused on four pesticides and performed in 18 farms in the Netherlands. Dermal exposure measured by using long-sleeved cotton gloves is strongly related to the amount of dislodgeable foliar residue (DFR). A transfer factor from leaves to hands of approximately 4500 cm2/hr (one-sided projected area) has been calculated. Small differences have been noticed between the different pesticides. Dermal exposure of hands and forearms to pesticides during cutting of carnations can be predicted from measurements of DFR. The DFR was mainly determined by the amount of pesticide remaining from previous applications and the last application rate, not by the application technique (spraying or dusting). The concentrations in the breathing zone after dusting of zineb (dustable powder) and chlorothalonil (wettable powder) were significantly correlated with the dislodgeable foliar residue. The concentrations of thiram did not correlate with DFR. Respiratory exposure results from dispersion of foliar dust containing pesticides.     

Exposure to styrene and health complaints in the Dutch glass-reinforced plastics industry.

A study of the health hazards for workers exposed to styrene in the Dutch glass-reinforced plastics industry was undertaken. The open mould techniques of filament winding, spraying and hand laminating were chosen for study because exposure of workers using them was expected to be high. Occupational hygiene surveys were conducted in four plants. In addition to measurements of exposure, data on health complaints were collected. In 12 smaller plants exposure was estimated in walk-through surveys. The results show that although most of the plants had implemented control measures such as ventilation and extraction, the levels of exposure constituted a health risk. Time-weighted average concentrations for workers involved in filament winding ranged from 134 to 716 mg m-3, for those who were spraying from 48 to 602 mg m-3 and for those laminating manually from 18 to 538 mg m-3. The 'no-adverse-effect level' based on effects observed in man is considered to be 105 mg m-3, and the acute subjective health effects experienced by the population studied supported this value. To reduce exposure to below 105 mg m-3, control measures should combine engineering with codes of practice adapted to the particular process or processes employed.     

Renal function of workers with low-level cadmium exposure

The influence of occupational exposure to cadmium on renal function was examined in 27 male cadmium workers from plants with second-degree usage of cadmium. The levels of cadmium in the blood and urine and various protein concentrations in the urine and serum were determined. The urinary levels of beta 2-microglobulin, retinol-binding protein, and N-acetyl-beta-D-glucosaminidase were statistically significantly increased in workers with urinary cadmium levels above 50 nmol/l. SDS-PAGE electrophoresis with silver staining is probably a sensitive indicator of the early effects of cadmium on protein excretion. The currently recommended biological exposure limits may have to be lowered.     

Doppler waveform of the hepatic veins in an obese population

The objective is to investigate the effect of obesity and hepatosteatosis on the Doppler waveform pattern of the hepatic veins. B-mode and duplex Doppler sonography of the liver and the right hepatic vein was performed in 102 obese subjects and 84 healthy volunteers. The severity of fatty infiltration was graded as mild, moderate and severe. The flow pattern of the right hepatic vein was classified as triphasic, biphasic and monophasic. The Doppler flow pattern in the right hepatic vein was triphasic in 56 (55%), biphasic in 27 (26%) and monophasic in 19 (19%) obese patients, whereas it was triphasic in 83 (99%) and biphasic in 1 (1%) control subject, achieving a statistical significance (Mann-Whitney U-test, P<0.001). There was an inverse correlation between the sonographic grade of the hepatosteatosis and the phasicity of hepatic venous flow (r=–0.67, P<0.001). The hepatic vein pulsatility is significantly dampened in obese patients correlating with the grade of hepatosteatosis. The body habitus itself does not have an independent effect on hepatic venous waveform. The alteration in hepatic vein Doppler flow pattern in an obese population may suggest reduced vascular compliance in the liver because of fatty infiltration.This revised version was published online in October 2004 with corrections to the author names. The authors are: Nevzat Karabulut, Selçuk Kazil, Baki Yagci, Nuran Sabir.     

Effects of Fagonia cretica L. constituents on various haematological parameters in rabbits

Effects of powdered Fagonia cretica plant and its two major triterpenoid saponins (saponin-I and saponin-II), isolated from its ethanolic extract, on red blood cells (RBC) count, haemoglobin concentration (HC), mean corpuscular haemoglobin (MCH) and on total leucocyte (WBC) count of normal male rabbits were investigated. Saponins treated three dose groups of animals indicated significant decrease in RBC count during the experimental period of 16 days. This effect was more pronounced in animals treated with saponin-II than saponin-I. The 0.50 and 1.0g crude drug treated animals and 10 and 20mg of both the saponins treated animals, indicated a decreasing tendency of HC up to the 4th day, which increased afterwards up to the 16th day. The third dose of these materials (1.50g of crude drug and 30mg of both saponins) exhibited a highly significant decreasing pattern, up the 16 days. The decreasing effect of haemoglobin concentration was more distinct in the saponin-II treated animals than saponin-I and the crude drug. The MCH followed a reverse pattern than RBC and HC. A continued decreasing trend was found in total WBC during the 16 days treatment. An amount of 1.50g of the crude drug and 30mg of both the saponins had highly significant decreasing effects on the amount of total leukocyte count of rabbit's blood.     

A rare presentation of hydatid cyst

Hydatid disease, although known to occur in most body areas, is extremely rare in the female reproductive system. There are different modes of presentation for the disease; however, we report and discuss a case presented with cystic vesicles passing through the vagina, which is considered as a rare presentation for secondary involvement of the uterus and both ovaries. We confirmed diagnosis with radiological examinations and serological tests. We operated on the patient, and studied the excised cysts microscopically. The gynecologist should be aware of hydatid cyst when vaginally passing a grape like vesicle is presented by the patient.     

Dermal absorption of chlorpyrifos in human volunteers

Objective: The methods and results are described of a study on the dermal absorption of chlorpyrifos (CPF) in humans established via urinary excretion of the metabolite 3,5,6-trichloro-2-pyridinol (TCP). Methods: Two dermal, single, doses of CPF were applied in two study groups (A and B) each comprising three apparently healthy male volunteers who gave their written informed consent. The clinical part of the study was conducted in compliance with the ICH Guideline and the EC principles of good clinical practice (GCP). An approximately 0.5 ml dilution of CPF in ethanol was applied to an area of ~100 cm² of the volar aspect of the forearm, resulting in doses of either 5 mg (A) or 15 mg (B) of CPF per study subject. Duration of dermal exposure was 4 h, after which the non-absorbed fraction was washed off. The following samples were collected at pre-determined intervals for the determination of either CPF or its metabolite TCP: dosing solutions, wash-off fractions and urine samples collected up to 120 h after dosing. Results: A relatively large fraction of CPF (42%–67% of the applied dose) was washed off from the exposed skin area. Application of either 5 mg (A) or 15 mg CPF (B) resulted in the total urinary excretion of 131.8 g (A) or 115.6 g (B) of TCP 120 h after dosing. This indicated that 4.3% of the applied dose has been absorbed (A), while in group (B) no significant increase in urinary TCP (115.6 g) was established. The latter indicates that an increase in the dermal dose at a fixed area does not increase absorption, which suggests that the percutaneous penetration rate was constant. Further, it was observed that the clearance of CPF by the body was not completed within 120 h, suggesting that CPF or TCP was retained by the skin and/or accumulated in the body. A mean elimination half-life of 41 h was established. Conclusion: The results show that daily occupational exposure to CPF may result in accumulation of CPF and/or its metabolites, possibly resulting in adverse effects.