Oral cadmium exposure during rat pregnancy: assessment of transplacental micronutrient transport and steroidogenesis at term.

Diet is the main source of cadmium (Cd) exposure. Gastrointestinal absorption increases during pregnancy. Cadmium accumulated in the placenta may interfere with nutrient transport to the foetus. Data on the potential of Cd to act as a steroid disruptor of pregnancy are limited. We evaluated the effects of oral Cd exposure during pregnancy on placental function in micronutrient transfer to the foetus and steroidogenesis in Wistar rats (regular 4-day cyclers) that mated with unexposed males. Pregnant rats were randomly assigned to a Cd group exposed orally to 50 mg Cd l(-1) (CdCl(2)xH2O dissolved in demineralized water), ≈ 7.5 mg Cd kg(-1) a day, during 20 days of gestation and control (supplied with demineralized water). Non-pregnant rats were treated under the same experimental conditions. On day 20, all of the rats were killed and samples were taken for element analyses (by electrothermal atomic absorption spectrometry). Progesterone and testosterone were measured in serum and placenta-derived samples (by immunoenzymometric assay and/or enzyme-linked immunosorbent assay). In the exposed rats, Cd increased in blood and organs, more in pregnant rats, and in placenta and foetus whereas zinc increased in liver. Iron decreased in maternal organs and in foetus, whereas zinc decreased in maternal kidney and placenta. Liver copper was lower and kidney copper higher in all pregnant vs. non-pregnant rats. Steroids in serum and placenta did not change. In conclusion, oral Cd exposure during rat pregnancy does not affect progesterone and testosterone at term. Transplacental iron and zinc handover are disrupted, which may put at risk the maintenance of foetal nutrition and viability.

Response to thermal and physical strain during flashover training in Croatian firefighters.

Flashover training (FOT) for firefighters is a simulation of the flashover phenomenon under controlled conditions. This study assessed arterial blood pressure (BP) and its response to thermal and physical strain during FOT in 48 professional and 18 volunteer firefighters. A high prevalence of obesity (27%), basal hypertensive (53%) and prehypertensive (33%) BP values was found. FOT induced mild hyperthermia and physical strain (average increase of 1.1 °C in tympanic temperature and 61% of the maximal heart beat predicted for age). Compared to professional firefighters, FOT in the volunteers induced a higher increase in pulse (P = 0.050) and tympanic temperature (P = 0.025). Systolic BP did not vary significantly, and diastolic BP slightly decreased in both groups. Results confirm that FOT induced only physiological cardiovascular responses to thermal and physical strain in firefighters. High prevalence of obesity and elevated BP values indicate the need for better physical fitness and BP control among firefighters.

Relevance of serum copper elevation induced by oral contraceptives: a meta-analysis.

BACKGROUND AND STUDY DESIGN: It is well documented that copper (Cu) blood levels are elevated in combination oral contraceptive (COC) users. The aim of this study was to establish the range of Cu increase in OC users compared to nonusers through a systematic literature overview and quantitative data analysis. RESULTS: Twenty-six articles were included in the meta-analysis. The increase in Cu level exponentially decreased in COC users over time, with a rapid decline through the 1960s and 1970s. After controlling for the publication year, use of COC increases the mean serum/plasma Cu level by 0.57 mg/L (95% confidence interval 0.49-0.66 mg/L). CONCLUSION: COCs commonly raise serum Cu to levels between 1.5 and 2 mg/L, which are above reference levels. Although these levels are not considered toxic, there are suggestions that such Cu increase could be implicated in oxidative pathophysiological processes in the body. Further research on safety of COCs use, including oxidative-stress-related effects, is warranted.

Acute effects of smoking and food consumption on breath condensate pH in healthy adults.

Acute effects of food and cigarette consumption on exhaled breath condensate (EBC) acidity are insufficiently explored. The study aimed to evaluate potential changes in EBC pH within 2 hours following cigarette or food consumption. In 15 healthy smokers, samples were obtained after 10 hours of abstinence from smoking and then 15, 30, 60, and 120 minutes after smoking 1 cigarette. In 19 healthy nonsmoking adults, EBC samples were obtained in the morning after an overnight fast, and then 30, 60, and 120 minutes following standardized breakfast. Smoking of 1 cigarette after overnight tobacco abstinence induced significant increase in EBC pH during the 2-hour observation period, for approximately 0.60 logarithmic units (repeated-measures analysis of variance [ANOVA], P < .0001). The average presmoking pH value in smokers (7.00 ± 0.50) was significantly lower than average value in nonsmokers (7.62 ± 0.31; P = .0001). No effect of food consumption was found. These results show that cigarette smoking acutely increases EBC pH in healthy smokers. Smoking status and abstinence from smoking before EBC sampling seems to be important in studies evaluating EBC pH and should be standardized or at least stated in the methodology. Acute effects of food were not found under described study conditions in healthy adults.

Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin.

Cadmium and other metallic ions can act as metalloestrogens and endocrine disruptors of reproductive tissues and fetal development in mammals, including humans. The detrimental effects occur with respect to the synthesis of both steroid and polypeptide hormones in the placenta. Leptin is produced by the trophoblast and may regulate fetal organogenesis and development. In human term placentas, concentrations of toxic metals and their effects on steroidogenesis were assessed in healthy parturients (109 non-smokers and 99 smokers) in relation to tobacco smoking. Trace elements (cadmium, lead, iron, zinc and copper) were analyzed in placentas using atomic absorption spectroscopy, and steroid hormones (progesterone and estradiol) were assayed in placental samples by an enzyme-immunometric method. Cadmium concentrations were doubled in placentas of smokers as compared with non-smokers, and placental lead and zinc concentrations increased significantly. Placental concentrations of iron, copper, progesterone and estradiol did not differ. In addition, human trophoblast cells were co-cultured with 0, 5, 10 or 20 microm CdCl(2) for 96 h and leptin mRNA assessed by quantitative polymerase chain reaction. Leptin mRNA declined dose-responsively as a result of CdCl(2) exposure. Collectively, the results confirm that human placental tissue offers a unique opportunity to biomonitor cadmium exposure in both the maternal and the internal fetal environments. In addition, the results strongly suggest that cadmium may cause a decline in placental leptin synthesis, as we have previously shown for placental progesterone production. This may constitute further evidence of the endocrine-disrupting effects of cadmium, as a constituent of tobacco smoke, on reproduction in women.

Exposure to poultry dust and health effects in poultry workers: impact of mould and mite allergens.

PURPOSE: The aim of the study was to evaluate exposure to moulds and house dust mite Dermatophagoides pteronyssinus in poultry farms, and related health effects in poultry workers (PW). METHODS: The study involved 41 PW and 45 control office workers. Working environment was evaluated for D. pteronyssinus allergen (Der p 1), moulds and endotoxin. In workers, eye, skin and respiratory symptoms, ventilatory lung function, atopy markers (skin prick test to inhalatory allergens, total IgE) and specific IgG to moulds were assessed. RESULTS: Der p 1 levels ranged <0.1-3.3 microg/g, exposure to fungi was 4.9 x 10(3)-6.8 x 10(4) cfu/m(3), with prevailing Aspergillus, Penicillium and Mucor species, and endotoxin levels ranged 230-284 EU/m(3). In comparison to control subjects, significantly higher prevalence of work-related nose, asthma, eye and skin symptoms, and slight decline in ventilatory lung function was found in PW. PW had significantly higher prevalence of IgG antibodies to moulds comparing to controls (63 vs. 36%, respectively, P = 0.01), especially to Alternaria and Aspergillus species. The prevalence of atopy markers in PW was lower than in population-based studies. CONCLUSIONS: Hazardous levels of Der p 1, endotoxin and moulds were determined in poultry houses. High prevalence of work-related symptoms and IgG antibodies to moulds was found in PW. Healthy worker effect is proposed as an explanation of low atopy markers prevalence among PW.

Exhaled breath condensate pH in adult Croatian population without respiratory disorders: how healthy a population should be to provide normative data?

The aim of this study was to obtain preliminary exhaled breath condensate (EBC) pH values for healthy adult Croatian subjects, and to evaluate criteria for defining respiratory health of population providing normal EBC pH values in epidemiologic studies. In 109 adults without a history of lower airway symptoms (AS), four groups were described by narrowing the definition of "health" down to 1) without lower AS; 2) without lower and upper AS; 3) without AS, with normal FEV(1) and bronchial normoreactivity; 4) without AS, with normal FEV(1), bronchial normoreactivity, normal total IgE, and with negative skin prick test. Median EBC pH values did not differ between the groups (7.72, 7.73, 7.73, 7.73), but as health criteria got stricter, we observed a slight, nonsignificant increase in minimal pH values (6.95, 7.10, 7.20, 7.37). Median EBC pH values with interquartile range in the total sample (7.72; 7.63 to 7.76) were within the range previously reported by other authors. They did not differ regarding sex, smoking habit and atopic status, and were not associated with age, FEV(1) or total IgE. The non-significant trend in EBC pH observed with stricter criteria of respiratory health and atopic status indicates the need for further research on criteria for defining healthy population in a larger sample.

The role of polio-vaccine in pleural mesothelioma--an epidemiological observation.

From the Croatian Cancer Registry (period 1991-1997) 194 malignant pleural mesothelioma patients were collected. According to participation in polio vaccination mass campaign in 1961 that covered the entire Croatian population aged 3 months to 20 years, mesothelioma patients were divided in vaccinated (N=58), and non-vaccinated (N=136) subjects. Significantly higher percentage of those with a history of occupational exposure to asbestos was found in vaccinated (79%) compared to non-vaccinated group (63%). This is the opposite to what would be expected if potential SV40 contamination of polio vaccine used had a causative role in the development of the tumour. On the other hand, shorter latency period reflected by very high percentage of 45-year-old or younger mesothelioma patients in vaccinated group (15 out of 58), with all of them having a history of occupational asbestos exposure, raises a question for a possible enhancing effect of the vaccine used to asbestos exposure, if it was contaminated with SV40.

Chelators as antidotes of metal toxicity: therapeutic and experimental aspects.

The effects of chelating drugs used clinically as antidotes to metal toxicity are reviewed. Human exposure to a number of metals such as lead, cadmium, mercury, manganese, aluminum, iron, copper, thallium, arsenic, chromium, nickel and platinum may lead to toxic effects, which are different for each metal. Similarly the pharmacokinetic data, clinical use and adverse effects of most of the chelating drugs used in human metal poisoning are also different for each chelating drug. The chelating drugs with worldwide application are dimercaprol (BAL), succimer (meso-DMSA), unithiol (DMPS), D-penicillamine (DPA), N-acetyl-D-penicillamine (NAPA), calcium disodium ethylenediaminetetraacetate (CaNa(2)EDTA), calcium trisodium or zinc trisodium diethylenetriaminepentaacetate (CaNa(3)DTPA, ZnNa(3)DTPA), deferoxamine (DFO), deferiprone (L1), triethylenetetraamine (trientine), N-acetylcysteine (NAC), and Prussian blue (PB). Several new synthetic homologues and experimental chelating agents have been designed and tested in vivo for their metal binding effects. These include three groups of synthetic chelators, namely the polyaminopolycarboxylic acids (EDTA and DTPA), the derivatives of BAL (DMPS, DMSA and mono- and dialkylesters of DMSA) and the carbodithioates. Many factors have been shown to affect the efficacy of the chelation treatment in metal poisoning. Within this context it has been shown in experiments using young and adult animals that metal toxicity and chelation effects could be influenced by age. These findings may have a bearing in the design of new therapeutic chelation protocols for metal toxicity.