Discriminant Profiles of Volatile Compounds in the Alveolar Air of Patients with Squamous Cell Lung Cancer, Lung Adenocarcinoma or Colon Cancer

The objective of the present work was to analyze volatile compounds in alveolar air in patients with squamous cell lung cancer, lung adenocarcinoma or colon cancer, to prepare algorithms able to discriminate such specific pathological conditions. The concentration of 95 volatile compounds was measured in the alveolar air of 45 control subjects, 36 patients with lung adenocarcinoma, 25 patients with squamous cell lung cancer and 52 patients with colon cancer. Volatile compounds were measured with ion molecule reaction mass spectrometry (IMR-MS). An iterated least absolute shrinkage and selection operator multivariate logistic regression model was used to generate specific algorithms and discriminate control subjects from patients with different kinds of cancer. The final predictive models reached the following performance: by using 11 compounds, patients with lung adenocarcinoma were identified with a sensitivity of 86% and specificity of 84%; nine compounds allowed us to identify patients with lung squamous cell carcinoma with a sensitivity of 88% and specificity of 84%; patients with colon adenocarcinoma could be identified with a sensitivity of 96% and a specificity of 73% using a model comprising 13 volatile compounds. The different alveolar profiles of volatile compounds, obtained from patients with three different kinds of cancer, suggest dissimilar biological–biochemistry conditions; each kind of cancer has probably got a specific alveolar profile.

Health-related quality of life varies in different respiratory disorders: a multi-case control population based study

BACKGROUND AND OBJECTIVE

Health-related quality of life (HRQL) in respiratory diseases has been generally investigated in clinical settings, focusing on a single disorder. In this study on a general population sample, we assessed the relationship between HRQL and several respiratory diseases studied simultaneously (COPD, current (CA) and past (PA) asthma, allergic (AR) and non-allergic (NAR) rhinitis and chronic bronchitis (CB).

METHODS

Controls (n = 328) and cases of NAR (n = 95), AR (n = 163), CB (n = 48), CA (n = 224), PA (n = 126) and COPD (n = 28) were recruited in the centre of Verona in the frame of the Italian multi-case control GEIRD (Gene Environment Interactions in Respiratory Diseases) study; HRQL was measured through the SF-36 questionnaire. The relationships between HRQL (in terms of Physical (PCS) and Mental Component Scores (MCS)), respiratory diseases, and covariates were evaluated.

RESULTS

With respect to controls, the adjusted PCS median score was worse in subjects suffering from current asthma (- 1.7; 95%CI:-2.8;-0.6), CB (- 3.8; 95%CI:-5.7;-1.9), and COPD (- 5.6; 95%CI:-8.1;-3.1). MCS was worse in current asthmatics (- 2.2; 95%CI:-4.1;-0.3), CB (- 5.5; 95%CI:-8.7;-2.2), and COPD cases (- 4.6; 95%CI:-8.8;-0.5) as well.

CONCLUSIONS

To our knowledge, this is the first study in the general population that analyzed HRQL performing a simultaneous comparison of HRLQ in several respiratory disorders. We found that subjects suffering from COPD, CA, and CB had the poorest HRQL. Clinicians should carefully consider the possible impact of respiratory disorders as CB and not only that of CA and COPD.

Hepcidin and DNA promoter methylation in hepatocellular carcinoma

BACKGROUND

The liver hormone hepcidin regulates iron homoeostasis that is often altered in hepatocellular carcinoma (HCC). Epigenetic phenomena control gene expression through a dynamic fashion; therefore, considering the plasticity of both iron homoeostasis and epigenetic mechanisms and their role in liver carcinogenesis, we investigated whether hepcidin gene (HAMP) expression is modulated by DNA methylation, thus affecting iron status in human HCC.

MATERIALS AND METHODS

Thirty-two patients affected by nonviral HCC were enrolled, and their main clinical and biochemical characteristics were obtained. Neoplastic and homologous non-neoplastic liver tissues were analysed for HAMP promoter DNA methylation, for HAMP gene expression and for iron content. An in vitro demethylation assay with a human hepatocarcinoma cell line was performed to evaluate the role of DNA methylation on HAMP transcriptional repression.

RESULTS

Gene expression and DNA methylation analyses on tissues showed that HAMP was transcriptionally repressed in HCC tissues consensually with a promoter hypermethylation. Furthermore, patients with HCC had low serum hepcidin concentrations, and HCC tissues had relative iron depletion as compared to non-neoplastic liver tissues. The cell culture model showed the functional role of DNA hypermethylation by downregulating HAMP gene expression. Through a quantitative methylation analysis on HCC tissues, we then proved that methylation at definite CpG sites within consensus sequences for specific transcription factors is possibly the mechanism underlying HAMP repression.

CONCLUSIONS

This study highlights a novel role for HAMP downregulation through DNA promoter hypermethylation and emphasises the significance of epigenetics in the regulation of iron metabolism in HCC.

Inflammatory bowel disease and patterns of volatile organic compounds in the exhaled breath of children: A case-control study using Ion Molecule Reaction-Mass Spectrometry

Inflammatory bowel diseases (IBD) profoundly affect quality of life and have been gradually increasing in incidence, prevalence and severity in many areas of the world, and in children in particular. Patients with suspected IBD require careful history and clinical examination, while definitive diagnosis relies on endoscopic and histological findings. The aim of the present study was to investigate whether the alveolar air of pediatric patients with IBD presents a specific volatile organic compounds’ (VOCs) pattern when compared to controls. Patients 10–17 years of age, were divided into four groups: Crohn’s disease (CD), ulcerative colitis (UC), controls with gastrointestinal symptomatology, and surgical controls with no evidence of gastrointestinal problems. Alveolar breath was analyzed by ion molecule reaction mass spectrometry. Four models were built starting from 81 molecules plus the age of subjects as independent variables, adopting a penalizing LASSO logistic regression approach: 1) IBDs vs. controls, finally based on 18 VOCs plus age (sensitivity = 95%, specificity = 69%, AUC = 0.925); 2) CD vs. UC, finally based on 13 VOCs plus age (sensitivity = 94%, specificity = 76%, AUC = 0.934); 3) IBDs vs. gastroenterological controls, finally based on 15 VOCs plus age (sensitivity = 94%, specificity = 65%, AUC = 0.918); 4) IBDs vs. controls, built starting from the 21 directly or indirectly calibrated molecules only, and finally based on 12 VOCs plus age (sensitivity = 94%, specificity = 71%, AUC = 0.888). The molecules identified by the models were carefully studied in relation to the concerned outcomes. This study, with the creation of models based on VOCs profiles, precise instrumentation and advanced statistical methods, can contribute to the development of new non–invasive, fast and relatively inexpensive diagnostic tools, with high sensitivity and specificity. It also represents a crucial step towards gaining further insights on the etiology of IBD through the analysis of specific molecules which are the expression of the particular metabolism that characterizes these patients.

Methodology to define biological reference values in the environmental and occupational fields: the contribution of the Italian Society for Reference Values (SIVR)

BACKGROUND

Biological reference values (RVs) explore the relationships between humans and their environment and habits. RVs are fundamental in the environmental field for assessing illnesses possibly associated with environmental pollution, and also in the occupational field, especially in the absence of established biological or environmental limits.

OBJECTIVES

The Italian Society for Reference Values (SIVR) determined to test criteria and procedures for the definition of RVs to be used in the environmental and occupational fields.

METHODS

The paper describes the SIVR methodology for defining RVs of xenobiotics and their metabolites. Aspects regarding the choice of population sample, the quality of analytical data, statistical analysis and control of variability factors are considered. The simultaneous interlaboratory circuits involved can be expected to increasingly improve the quality of the analytical data.

RESULTS

Examples of RVs produced by SIVR are presented. In particular, levels of chromium, mercury, ethylenethiourea, 3,5,6-trichloro-2-pyridinol, 2,5-hexanedione, 1-hydroxypyrene and t,t-muconic acid measured in urine and expressed in micrograms/g creatinine (μg/g creat) or micrograms/L (μg/L) are reported.

CONCLUSIONS

With the proposed procedure, SIVR intends to make its activities known to the scientific community in order to increase the number of laboratories involved in the definition of RVs for the Italian population. More research is needed to obtain further RVs in different biological matrices, such as hair, nails and exhaled breath. It is also necessary to update and improve the present reference values and broaden the portfolio of chemicals for which RVs are available. In the near future, SIVR intends to expand its scientific activity by using a multivariate approach for xenobiotics that may have a common origin, and to define RVs separately for children who may be exposed more than adults and be more vulnerable.

Citrate-stabilized lanthanide-doped nanoparticles: brain penetration and interaction with immune cells and neurons

Aim: To unravel key aspects of the use of lanthanide-doped nanoparticles (NPs) in biomedicine, the interaction with immune and brain cells. Materials & methods: Effects of citrate-stabilized CaF2 and SrF2: Yb, Er NPs (13–15 nm) on human dendritic cells and neurons were assessed in vitro. In vivo distribution was analyzed in mice at tissue and ultrastructural levels, and with glia immunophenotyping. Results: The NPs did not elicit dendritic cell activation and were internalized by cultured neurons, without viability changes. After intravenous injection, NPs were found in the brain parenchyma, without features of glial neuroinflammatory response. Conclusion: Lanthanide-doped NPs do not activate cells protagonists of systemic and brain immune responses, are endocytosed by neurons and can cross an intact blood–brain barrier.

An Interleukin 13 Polymorphism Is Associated with Symptom Severity in Adult Subjects with Ever Asthma

Different genes are associated with categorical classifications of asthma severity. However, continuous outcomes should be used to catch the heterogeneity of asthma phenotypes and to increase the power in association studies. Accordingly, the aim of this study was to evaluate the association between single nucleotide polymorphisms (SNPs) in candidate gene regions and continuous measures of asthma severity, in adult patients from the general population. In the Gene Environment Interactions in Respiratory Diseases (GEIRD) study (www.geird.org), 326 subjects (aged 20–64) with ever asthma were identified from the general population in Verona (Italy) between 2007 and 2010. A panel of 236 SNPs tagging 51 candidate gene regions (including one or more genes) was analysed. A symptom and treatment score (STS) and pre-bronchodilator FEV₁% predicted were used as continuous measures of asthma severity. The association of each SNP with STS and FEV₁% predicted was tested by fitting quasi-gamma and linear regression models, respectively, with gender, body mass index and smoking habits as potential confounders. The Simes multiple-test procedure was used for controlling the false discovery rate (FDR). SNP rs848 in the IL13 gene region (IL5/RAD50/IL13/IL4) was associated with STS (TG/GG vs TT genotype: uncorrected p-value = 0.00006, FDR-corrected p-value = 0.04), whereas rs20541 in the same gene region, in linkage disequilibrium with rs848 (r² = 0.94) in our sample, did not reach the statistical significance after adjusting for multiple testing (TC/CC vs TT: uncorrected p-value = 0.0003, FDR-corrected p-value = 0.09). Polymorphisms in other gene regions showed a non-significant moderate association with STS (IL12B, TNS1) or lung function (SERPINE2, GATA3, IL5, NPNT, FAM13A) only. After adjusting for multiple testing and potential confounders, SNP rs848 in the IL13 gene region is significantly associated with a continuous measure of symptom severity in adult subjects with ever asthma.

Multifunctional nanoprobes based on upconverting lanthanide doped CaF2: towards biocompatible materials for biomedical imaging

Lanthanide doped CaF₂ nanoparticles are useful for in vivo optical and MR imaging and as nanothermometer probes, which do not induce pro-inflammatory cytokine secretion.

Serum hepcidin levels and muscle iron proteins in humans injected with low- or high-dose erythropoietin

Inhibition of hepcidin expression by erythropoietic signals is of great physiological importance; however, the inhibitory pathways remain poorly understood. To investigate (i) the direct effect of erythropoietin (Epo) and (ii) the contribution of putative mediators on hepcidin repression, healthy volunteers were injected with a single dose of Epo, either low (63 IU/kg, n = 8) or high (400 IU/kg, n = 6). Low-dose Epo provoked hepcidin down-modulation within 24 h; the effect was not immediate as hepcidin circadian variations were still present following injection. High-dose Epo induced no additional effect on the hepcidin response, that is hepcidin diurnal fluctuations were not abolished in spite of extremely high Epo levels. We did not find significant changes in putative mediators of hepcidin repression, such as transferrin saturation, soluble transferrin receptor, or growth differentiation factor 15. Furthermore, the potential hepcidin inhibitor, soluble hemojuvelin, was found unaltered by Epo stimulation. This finding was consistent with the absence of signs of iron deficiency observed at the level of skeletal muscle tissue. Our data suggest that hepcidin repression by erythropoietic signals in humans may not be controlled directly by Epo, but mediated by a still undefined factor.

Mild asthma and chronic bronchitis seem to influence functional exercise capacity: a multi-case control study

BACKGROUND

In the Genes Environment Interaction in Respiratory Diseases population-based multi-case control study, we investigated whether asthma, chronic bronchitis (CB) and rhinitis were associated with a reduced 6-minute walk distance (6MWD), and whether the 6MWD determinants were similar for subjects with/without respiratory diseases.

METHODS

Cases of asthma (n = 360), CB (n = 120), rhinitis (n = 203) and controls (no respiratory diseases: n = 302) were recruited. The variation in the 6MWD across the groups was analyzed by ANCOVA, adjusting for gender, age, height, weight and comorbidity. The 6MWD determinants were studied by linear regression, and heterogeneity across the cases and controls was investigated.

RESULTS

The 6MWD differed across cases and controls (p = 0.01). It was shorter for cases of asthma (-17.1, 95% CI -28.3 to -5.8 m) and CB (-20.7, 95% CI: -36.6 to -4.8 m) than for controls (604 ± 68 m on average), but not for cases of rhinitis. The negative association between age and the 6MWD was significant for cases of CB, but not for the other groups (p = 0.001).

CONCLUSIONS

Even at the level of severity found in the general population, asthma and CB could influence the 6MWD, which seems to reflect the functional exercise level for daily physical activities. The negative association between ageing and the 6MWD was particularly strong in subjects with CB. Our report adds to the mounting evidence that CB is not a trivial condition, especially in the ageing adult population, and it supports the importance of monitoring functional capacity and of physical reconditioning in mild asthma.

MMPI-2 personality profiles and suicidal ideation and behavior in victims of bullying at work: a follow-up study

The main aim of this study was to investigate longitudinally the personality profile and suicidal ideation and behavior in victims of bullying at work in relation to the evolution of the victimization. Forty-eight victims were evaluated by means of medical and psychological assessment including the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). A follow up session was carried out after an average of 22 months. At first evaluation, the average MMPI-2 personality profile of victims showed abnormal elevations on scales Hs (Hypochondria), D (Depression), Hy (Hysteria), and Pa (Paranoia), which were strikingly similar to that found in previous studies. Furthermore, suicidal ideation and behavior were common among victims. At follow-up, 26 victims reported that the degree of bullying had remained the same or had even worsened, whereas 22 said that the situation had improved or had been resolved. Although there was a trend toward normalization in the MMPI-2 profile for all victims, the profile of the "static" group was still abnormal at follow up. On the contrary, the profile of the "improved" group was entirely within normal range. Suicidal ideation and behavior decreased in all victims, but only to a significant degree in the improved group. Results are discussed in the light of the bullying process.

[Mental disorders related to persistent negative working conditions]

BACKGROUND

Mental disorders are common in our industrialised society and inevitably affect the working population. Over the last few years greater attention has been focussed on work-related psychopathologies due to an increasing number of studies regarding workplace bullying.

OBJECTIVES

This study reports our observations on patients with mental disorders who came to our Occupational Health Centre because they perceived themselves to be victims of negative working conditions. An indepth analysis of their working conditions led us to the conclusion that many of these disorders were to be attributed to the workplace.

METHODS

Between 2004 and 2010, 449 workers attended our Occupational Health Centre, most suffering from mental disorders which they ascribed to negative working conditions. All patients had an initial consultation session with an occupational physician which focused on the environmental and relational characteristics of their place of work. Thereafter, patients underwent a second clinical evaluation with a psychologist including several psychological tests. At the end of diagnostic process, the occupational physician and the clinical psychologist drew their clinical conclusions and defined the possible relationship with the working condition.

RESULTS

For 379 out of 449 patients/workers, a positive and causal relationship between medical disorders and working conditions was established. The mental disorders observed in these groups of workers were: mixed anxiety and depressive disorder (53.6%), depressive disorder (16.2%), adaptation disorder (15.9%), anxiety disorder (13%) and only 1.3% post-traumatic stress disorder. The working conditions favouring the mental disorders were: workplace bullying, such as person-related bullying (30.1%) and task-related bullying (14.8%), adverse situations causing work distress (38.2%) or non-specific work discomfort (16,9%).

CONCLUSIONS

Our experience showed that not only workplace bullying can cause different psychiatric disorders but also adverse situations that favour work distress and non-specific work discomfort often give raise to the same disorders. Negative working conditions can play a significant role in the development of psychological-psychiatric disorders: such disorders related to occupational conditions are on the increase in many industrialised countries.

[Occupational risk by the pine processionary moth Thaumetopoea pityocampa in the forestry workers of Verona]

Pine processionary moth (Thaumetopoea pityocampa) is a lepidopteran living in the Mediterranean countries whose mature larvae have microscopic hairs that can be released and carried far from the source. The hairs are responsible of urticating symptoms on the exposed areas although systemic manifestation might be involved. The study involved 94 forestry workers (92 M, 2 F) of the Regional Forest Service of Verona and the objective was to determine the prevalence of skin and respiratory disorders due to exposure to this insect. 21 chainsaw operators and 2 labourers experienced symptoms on exposed skin areas; 3 of them reported also ocular and respiratory symptoms. The chainsaw operators resulted most at risk whereas individual already suffering from others allergies do not seem to be affected. The results highlight the importance of risk assessment to Thaumetopoea pityocampa in forestry workers and the need for instruments to assess the allergic sensitization in medical surveillance.

[Work-related stress and psychological distress assessment in urban and suburban public transportation companies]

The risk of work-related stress has been determined in bus drivers and workers employed in the service department of two urban and suburban public transportation companies. The INAIL evaluation method (Check list and HSE indicator tool) was used. The GHQ-12 questionnaire, which is widely used to assess the level of psychological distress, was also employed. 81.9% of workers involved in the survey answered both the HSE indicator tool and the GHQ-12 questionnaire. The Check list evaluation showed an increase in quantifiable company stress indicators while close examination using the HSE indicator tool demonstrated critical situations for all the subscales, with the control subscales more problematic in bus drivers. The demand, manager's support, relationships and change subscales were most associated with psychological distress in bus drivers, while relationships, role, change and demand subscales were negatively related in workers of the service department.

[New varnishing techniques and health risk assessment]

The first part of the report signals the significant changes coating processes have endured over the last twenty years. The shift from traditional "solvent-based" paints to "water-based" paints marked a very important toxicological evolution, to reduce the possible toxic effects, to improve the products quality and to limit environmental pollution, Old and new recipes for preparation of paints and enamels are compared and discussed. The second part of the report summarizes the international literature concerning epidemiological data on painters and describes the toxic effects in experimental area that are reported for several solvents of water-based paints.

[The occupational physician and communication to workers]

Communication ability is essential for the Physician to the proper management of ambulatory activity and corporate training. The aim of this work is describe the communication strategies to be adopted in everyday healthcare practice. When the occupational physician relates with an employee his message must act both verbal both non-verbal. The medical history should be collected carefully and during the physical examination is important to put the employee at ease by adopting a discreet and attentive attitude. The clinical findings and the capacity to work with any limitations will be discussed at the end of health surveillance using understandable terminology to the worker. During the training-information process is important to define the primary objectives, organize the program and bring the display materials. The worker should be actively involved and encouraged to learn throughout the course information. In the text will also be shown the main aspects of information on line.

[The combined use of capillaroscopy and skin thermometry in health surveillance of workers exposed to hand-arm vibration]

The use of nailfold capillaroscopy combined with skin thermometry in the study of microcirculation of the hands in workers exposed to hand-arm vibration is assessed. Fifty-eight subjects were studied; 40 asymptomatic forestry workers exposed to hand-arm vibration, 13 forestry workers exposed to hand-arm vibration with Raynaud-like symptoms confirmed by skin thermometry; 5 controls. Reduction of capillary density was observed in workers exposed to vibrating tools with respect to controls. Tortuosity of capillary loops was significantly more frequent in subjects exposed to vibrating tools than in controls. No statistically significant difference in capillary vessels of the hands was found between asymptomatic exposed subjects and workers affected by Raynaud-like symptoms. In our sample nailfold capillaroscopy shows good sensibilty and specificity in detecting capillary modifications secondary to exposure to hand-vibration. Weaker evidence is instead given in order to actual disturbances of hands circulation in chronic exposure to vibrating tools.

[Analysis of body mass index in different sector workers for over ten years]

A critical review of the literature on obesity and overweight underlines that a low educational level, a low social-economic status, certain working conditions, the lack of physical activity in leisure time, together with the availability of food, are the main factors favouring increased prevalence of obesity. Certain jobs also contribute significantly to this problem. Automation, the use of machines for heavy works and sedentary activities favour body weight increase. Jobs that are a source of stress, such as work with night shift can cause metabolic disorders leading to an increased prevalence of obesity. The main aim of this article is to study the trend of body weight in different working area during ten years, comparing this parameter to different factors such as job, blood pressure, smoke, alcool and health diseases.

S-(acetamidomethyl)mercapturic acid (AMMA): a new biomarker for occupational exposure to N,N-dimethylacetamide

N,N-dimethylacetamide (DMA) is used in the textile and plastics industry as a solvent alternative to more toxic N,N-dimethylformamide. Here we studied toxicokinetics of two major urinary metabolites of DMA, namely, S-(acetamidomethyl)mercapturic acid (AMMA) and N-methylacetamide (NMA). Urine samples were collected from workers exposed to DMA in a factory manufacturing acrylic fibers. AMMA and NMA were determined by HPLC/MS and GC/MS, respectively. The working scheme in the factory consisted of periods of three consecutive working shifts alternated regularly with two days off work. In the first stage of the study, NMA and AMMA were determined in urine samples collected before, in the middle, and at the end of one working shift. In the second stage, urine was collected five times during three consecutive days after a two-day rest: before and at the end of the first and second working shifts and before the third shift. It was found that the end-of-shift NMA levels were several folds higher than the pre-shift levels of the same day and dropped significantly until the next shift. On the other hand, there were no significant differences in AMMA levels before and at the end of the same shift but a continuous rise during the three-day working period was observed. Median values of NMA concentrations at the end of working shifts were between 10.1 and 17.3 mg/g creatinine, median AMMA concentrations in the second or third day of the working period varied between 12.4 and 38.1 mg/g creatinine. The approximate half-lives of NMA and AMMA (means) in the exposed workers were about 9 and 29 h, respectively. Thus, while NMA in the end-of-shift urine samples remains a preferential biomarker of DMA exposure during that shift, AMMA determined at the end of a work-week reflects cumulative exposure over the last few days. Further studies are needed to determine AMMA concentrations corresponding to the threshold limit value of DMA.

The Gene-Environment Interactions in Respiratory Diseases (GEIRD) Project

The role of genetic and environmental factors, as well as their interaction, in the natural history of asthma, allergic rhinitis and chronic obstructive pulmonary disease (COPD) is largely unknown. This is mainly due to the lack of large-scale analytical epidemiological/genetic studies aimed at investigating these 3 respiratory conditions simultaneously. The GEIRD project is a collaborative initiative designed to collect information on biomarkers of inflammation and oxidative stress, individual and ecological exposures, diet, early-life factors, smoking habits, genetic traits and medication use in large and accurately defined series of asthma, allergic rhinitis and COPD phenotypes. It is a population-based multicase-control design, where cases and controls are identified through a 2-stage screening process (postal questionnaire and clinical examination) in pre-existing cohorts or new samples of subjects. It is aimed at elucidating the role that modifiable and genetic factors play in the occurrence, persistence, severity and control of inflammatory airway diseases, by way of the establishment of a historical multicentre standardized databank of phenotypes, contributed by and openly available to international epidemiologists. Researchers conducting population-based surveys with standardized methods may contribute to the public-domain case-control database, and use the resulting increased power to answer their own scientific questions.

Respiratory health effects and immunological response to Thermoactinomyces among sugar cane workers in Nicaragua

Specific sensitization and respiratory effects associated with the inhalation of sugar cane dust were evaluated in a group of 51 Nicaraguan workers exposed to bagasse. A questionnaire interview, lung function test, serum precipitin tests for Thermoactinomyces sacchari and T. vulgaris, and immunoglobulin E tests for specific environmental allergens were performed for each worker. Twenty-one workers reported at least one respiratory symptom and 16 reported possible symptoms of bagassosis. Six workers demonstrated acute symptoms, 1 had chronic symptoms, and 9 had the reacutized form of the disease. A higher proportion of precipitin response to T. sacchari and T. vulgaris was found in workers reporting symptoms suggestive of acute bagassosis. A possible restrictive ventilatory pattern was observed in 8 subjects and a mild airway obstruction in 1 subject. Priority must be given to a surveillance and exposure prevention program for workers employed in sugar cane production and processing.

Involvement of mitochondrial permeability transition pore opening in alpha-bisabolol induced apoptosis

Alpha-bisabolol is a natural monocyclic sesquiterpene alcohol. It has been used in cosmetics for hundreds of years because of its perceived skin-healing properties. Alpha-bisabolol is known to have anti-irritant, anti-inflammatory and antimicrobial properties. In precedent studies, we described how alpha-bisabolol exerts a selective pro-apoptotic action towards transformed cells [Cavalieri E et al. (2004) Biochem Biophys Res Commun 315, 589-594] and its uptake is mediated by lipid rafts on the plasma membrane [Darra E et al. (2008) Arch Biochem Biophys 476, 113-123]. In this study, we hypothesize that the intracellular target of alpha-bisabolol may be the mitochondrial permeability transition pore (mPTP). To evaluate this hypothesis, we used one transformed cell line (human glioma T67) in comparison with a nontransformed one (human fibroblasts). We assessed the effect of a specific mPTP inhibitor (cyclosporine A) on the toxic action of alpha-bisabolol. Results show that the alpha-bisabolol-induced decrease in oxygen consumption is abolished by the addition of cyclosporine A in T67 cells, indicating that alpha-bisabolol may target mPTP. The central role of mitochondria was also demonstrated by using galactose to force cells to a more aerobic metabolism. In this condition, we observed higher alpha-bisabolol toxicity. Furthermore, we studied the effect of alpha-bisabolol on isolated rat liver mitochondria. This study expands the notion of the specific action of alpha-bisabolol on transformed cells and suggests that it may act by disturbing the structure and function of the mPTP. Alpha-bisabolol toxicity is clearly related to its cellular uptake, which is higher in transformed cell lines.

[Noise-induced hearing loss: are health service surveillance programs always effective?]

OBJECTIVES

To evaluate noise-induced hearing loss in a group of workers at a steel engineering works over a 20 year period (1979-1999).

METHODS

A total of 2431 audiometric tests were performed in 708 workers (in 1979, 1984, 1989, 1994 and 1999). Audiometric tests were classified so that hearing loss could be assessed over time. Additionally, personal noise exposure was measured for each worker (average, 85 dB(A) in tests carried out in 1992, 1996 and 1999).

RESULTS

Over 5 years of noise exposure, mean cumulative incidence of noise-induced hearing loss was 8,2%. Over 10 years ofexposure (1979-89 or 1984-94 or 1989-99), the mean incidence was 15,3%. This percentage increased to 22,9% and 25,7% when the exposure lasted 15 or 20 years respectively.

CONCLUSIONS

The considerable incidence of noise-induced hearing loss within the wide group of steel workers examined greatly exceeds the expected incidence related to the occupational exposure limits. The Evidence Based Occupational Medicine suggests that our health surveillance was not effective enough.

Xenobiotic action on steroid hormone synthesis and sulfonation the example of lead and polychlorinated biphenyls

OBJECTIVES

In the present study, the metabolism of steroid hormones has been investigated to determine whether and how xenobiotics like lead (Pb) and polychlorinated biphenyls (PCBs) interfere with steroid hormone biotransformation in humans.

METHODS

Three groups of subjects were tested for concentration of urinary total steroids, 17-ketosteroids (n = 5), pregnane derivates (n = 6), 17-hydroxycorticosteroids (n = 11) and their sulfonated compounds: 14 workers exposed to lead, with a mean Pb blood concentration (PbB) of 29.21 microg/dl; 15 subjects exposed to PCBs, with a mean PCB blood concentration (PCBB) of 61.69 microg/l; a control group (n = 25).

RESULTS

The urinary concentrations of 17-ketosteroids and 17-hydroxycorticosteroids were significantly lower in the PCB-exposed groups. There were significantly fewer sulfonated 17-hydroxycorticosteroids in the subjects exposed to PCBs as compared to the controls, while the percentage of sulfonated steroids was lower for both 17-ketosteroids and 17-hydroxycorticosteroids in the PCB-exposed subjects, but only for the 17-hydroxycorticosteroids in the group of subjects exposed to Pb (P < 0.05). Pregnane derivate urinary concentrations did not differ between the three groups.

CONCLUSION

Our results suggest that PCBs and Pb act on steroid hormone metabolism with different effects and only partially using the same hormone pathways; they may cause changes in endogenous hormone homeostasis and interfere with the xenobiotic phase II of detoxification. PCBs interfere on a larger number of steroids and cause more significant effects than Pb. It is likely that different mechanisms are involved in steroid hormone metabolism interference.

Alpha-bisabolol: unexpected plant-derived weapon in the struggle against tumour survival?

Despite enormous scientific and economic effort tumour still is one of the most terrible pathologies among human population all over the world. Products derived from the plant kingdom have often offered an opportunity to counteract or alleviate this illness. Here, we summarize the short story of the study of an extraordinary effect of one plant compound towards transformed cells derived from highly malignant tumours. Alpha-bisabolol, a sesquiterpene widely present in plants, selectively kills transformed cells by apoptosis without affecting the viability of normal cells. One of its intracellular targets seems to be situated on mitochondria and is possibly identified as the permeability transition pore, as judged from rapid mitochondrial membrane potential dissipation induced by alpha-bisabolol and the failure to kill cells in the presence of cyclosporine A. Preferential adsorption of alpha-bisabolol into lipid rafts, rich in tumour cells, may explain the selective action of this compounds towards tumour cells. Furthermore, Surface Plasmon Resonance analysis indicates that alpha-bisabolol directly interacts with Bid protein, a member of the Bcl2 family deeply involved in apoptosis, suggesting a possibility that Bid, or similar protein(s), may be involved in a putative intracellular transport system of alpha-bisabolol from plasma membrane to mitochondria. Experiments with animals indicate that alpha-bisabolol is not toxic and is accumulated, through blood flow, in every tissues examined. Further animal studies to test its effect are currently under way.

Interethnic differences at the thermometric response to cold test: functional disorders of blood circulation in hand fingers and exposure to hand–arm vibration

OBJECTIVES

To report some notable aspects regarding thermometric response to cold test in black African subjects compared with Caucasians: both groups comprised persons exposed to hand-arm vibration and controls.

METHODS

An overall sample of 48 workers was examined in order to study their blood circulation in hand fingers: a control group of 12 healthy Caucasian workers never exposed before to hand-arm vibration; 12 Caucasian workers exposed for several years to vibrating tools and affected by occupational Raynaud's phenomenon; 12 healthy black African workers exposed to hand-arm vibration for almost 3 years; and 12 healthy black African workers never exposed to hand-arm vibration. Computerized skin thermometry was performed and thermometric curves were analyzed according to thermometric interpretation criteria such as the area-over-curve (AOC), the fifth minute of recovery/baseline temperature ratio (5REC/BT) and the temperature at the tenth minute of recovery (10REC) after cold test.

RESULTS

Thermometric parameters in Caucasian subjects confirmed the basis of the existing literature in controls (basal finger temperature higher than 32 degrees C and complete recovery to the initial temperature after the cold test) and also in patients with Raynaud's phenomenon (basal temperature often lower than control subjects and slow recovery of finger temperature after cold test). Statistically significant difference was found between healthy Caucasians and healthy black subjects in all the parameters tested: healthy black subjects showed values of AOC and 10REC suggesting almost constantly lower finger temperatures during the thermometry test. Black people, both exposed and non-exposed to hand-arm vibration showed thermometric parameters suggesting poor blood microcirculation, which seems even poorer than in Caucasian people complaining Raynaud's phenomenon.

CONCLUSIONS

Our chronothermometric tests suggest some significant interethnic differences in peripheral microcirculation, which seems rather poor in black African subjects in comparison with Caucasians.

[Prevalence of occupational allergic symptoms among bakers of Verona]

The aim of the study is to evaluate the prevalence of respiratory and skin symptoms among bakers in the district of Verona by means of two standardized questionnaires, a clinical one administered to the bakeries employees, either directly exposed to flour dust or not exposed, and one concerning the characteristics of the bakery environment. The study involved 613 bakery workers, 401 bakers and 212 sales personnel employed in 152 bakeries. Bakers exposed to flour dust reported nasal symptoms in 29.2% of cases, ocular symptoms in 13.2%, cough, shortness of breath, chest tightness, wheezing respectively in 8.7%, 7%, 4.5% 6.2% of cases, itch and skin burning with paleness respectively in 9.7% and 8.5%. A significantly lower prevalence of these symptoms, except skin paleness, was reported among the sales personnel. In bakers, a significant correlation was found between ocular-nasal and respiratory symptoms and family or self-reported history of atopy (p = 0.001). Reported flour dust air pollution at the workplace correlated with occupational ocular-nasal and respiratory symptoms (p = 0.001). Flour dust on skin and clothes correlated with crusts and excoriations (p = 0.01). Our study confirms the high prevalence of allergic symptoms among bakers and the need of clinical assessment.

[Follow up of person-related bullying and work-related bullying: evaluation of effectiveness of interventions]

Person-related bullying is regarded as a form of stress capable of cause negative effects on workers' health, potentially leading to psycho-physical symptoms, alterations of mood and personality, psychiatric disorders such as anxiety-depression disorder, chronic adjustment disorder and posttraumatic stress disorder. At the Centre for the study of psychosocial risks and pathologies at work of Verona the health state of victims of person-related bullying and work-related bullying and their working conditions are periodically evaluated. On a regular bases these workers receive psychological support and, if necessary, psychiatric treatment; at the same time interventions on working environment are undertaken when possible. Verification of effectiveness is then carried out by means of interviews starting six months after the first consultation. Two questionnaires are used; a specific one for the assessment of working environment and health conditions, and Goldberg's General Health Questionnaire--G.H.Q-12. Improvement of health state related to better working conditions was obtained in general.

[Evidence Based Occupational Medicine: ten year experience with audiometric examination in a handicraft company]

This work describes the audiometry threshold assessment of 1000 workers employed in different artisan categories during a period of ten-year noise professional exposure. The hearing loss noise-induced rates were determined by analysing audiometric tests at the beginning of our period of study and after 5 and 10 years of noise exposure. Environmental noise exposures were on average 88 dB(A), but near 90 dB(A) in some work categories. Workers widely used hearing protection devices, nearly at 93%, during the period we studied. The Evidence Based Occupational Medicine should find out points of reference proving the efficiency and effectiveness of occupational physicians: in this case, a positive trend in the reduction of hearing loss rate will be expected to confirm the goodness of prevention practice. Our study suggests that the levels of protection so far accepted are not effective enough in order to reduce the incidence of noise-induced hearing loss in the course of the years: in despite of most accredited predicting models for hearing conservation programs, a significant percentage of workers exposed to industrial noise continues to present a high incidence of hearing loss. The Evidence Based Occupational Medicine suggests that the proposed prevention activities carried out in the described factories were not enough effective.

DNA damage and repair capacity by comet assay in lymphocytes of white-collar active smokers and passive smokers (non- and ex-smokers) at workplace

The comet assay has been widely used to quantify DNA damage in isolated lymphocytes from subjects exposed to several environmental or occupational substances, especially for estimation of oxidative damage in the DNA, which is well-known to be induced by tobacco smoke. Passive smoking or environmental tobacco smoke (ETS) has been included among those substances that cause cancer with sufficient evidence in humans. In this study, we analyzed, by the alkaline version of comet assay, the lymphocyte DNA damage of white-collar active smokers and non- and ex-smokers exposed to ETS at the workplace. We investigated basal DNA damage, DNA oxidation by formamidopyrimidine glycosylase (Fpg), the repair capacity H2O2-induced DNA damage by kinetics studies and lymphocyte GSH levels, the major intracellular defense against exogenous oxidative stress imposed by cigarette smoking. Our results indicated high basal DNA damage with clear significant correlations with urinary nicotine and cotinine, number of cigarettes/day, and an inverse significant correlation with GSH cellular content in active smokers. Significant Fpg-sensitive sites were found in smokers (> 85%), considerably high but not significant in passive non- and ex-smokers (> 51% and 37%, respectively). The DNA repair capacity had seriously decreased in non-smokers > smokers > ex-smokers, while the same damage was repaired in a short time in never smokers.

Reference values for exhaled nitric oxide (reveno) study

Background

Despite the widespread use of fractional exhaled nitric oxide (FE_NO) as a biomarker of airways inflammation, there are no published papers describing normal FE_NO values in a large group of healthy adults.

Objective

The aim of this study was to establish adult FE_NO reference values according to the international guidelines.

Methods

FE_NO was measured in 204 healthy, non-smoking adults with normal spirometry values using the on-line single-breath technique, and the results were analysed chemiluminescently.

Results

The main result of the study was the significant difference in FE_NO values between men and women, thus indicating that gender-based reference FE_NO values are necessary. The FE_NO levels obtained at expiratory flows of 50 ml/s ranged from 2.6 to 28.8 ppb in men, and from 1.6 to 21.5 ppb in women.

Conclusion

We propose reference FE_NO values for healthy adult men and women that could be used for clinical and research purposes.

Evaluation of finger skin temperature in scleroderma patients cyclically treated with iloprost

OBJECTIVES

To evaluate by computerized digital thermometry (CDT) the effect of cyclic iloprost infusions on finger skin temperature (FST) in scleroderma patients.

METHODS

Twenty-two scleroderma outpatients (one man, 21 women, mean age 54.2 years) underwent three computerized digital thermometries, the first one 3 days before a 5-day cycle of iloprost infusion, the second the day of the fifth infusion soon after the end of the therapy and the third 1 month after. FST was evaluated under basal conditions, immediately after a cold test and after an 18 min recovery period. For comparison CDT was performed in 10 sex and age matched control subjects.

RESULTS

FST was lower in scleroderma patients before iloprost infusion than in the control group either after cold test either at the end of the recovery period while no difference was found before the cold test. Soon after iloprost infusion and 1 month later the FST at the end of the recovery period increased from the pre-treatment value of 27.8 +/- 5.3 to 30.4 +/- 3.5 degrees C and to 30.0 +/- 4.5 degrees C, respectively (P < 0.05 for both values). No substantial differences were found concerning FST before and at the end of the cold test.

CONCLUSION

Iloprost administration for 5 days allows to normalize the FST value after cold exposition not only immediately after the infusions but even at 1 month distance from the therapy. Despite its short half-life the effect of the drug on endothelium is protracted.

Determination of alpha-bisabolol in human blood by micro-HPLC-ion trap MS and head space-GC-MS methods

Alpha-bisabolol is a compound present in some essential oils, widely distributed in several plants, including camomile. Two different methods for analysing an essential oil, such as alpha-bisabolol in human blood are reported: the first uses micro-liquid chromatography-electrospray ionisation-mass spectrometry (muHPLC-ESI-MS), whereas the second is based on "head space" injection coupled to gas chromatography-mass spectrometry (HS-GC-MS). For LC-ESI-MS, human blood samples, spiked with alpha-bisabolol, were extracted with hexane and evaporated to dryness under air stream. The residue was then reconstituted with methanol and injected into a C18 column, connected to an ion trap mass spectrometer equipped with an ESI source. Spectra were recorded in the positive ion, selected ion monitoring mode. The detection limit of alpha-bisabolol in blood was 0.125 micromol/l. The preparation of samples for the analysis in HS-GC-MS was limited to blood dilution with water (0.5 ml blood + 1 ml water). Head space vials were heated at 125 degrees C for 1 h before automatic injection. The HS-GC-MS detection limit (0.13 micromol/l) was similar to that achieved with the muHPLC-ESI-MS method. Successful tests were performed to verify if alpha-bisabolol could be directly measured by the HS-GC-MS method in different biological samples (blood, urine, faeces, homogenate tissues) from rats treated with the camomile essential oil.

[New biomarkers of exposure]

In this paper we have defined the new biomarkers of exposure (NBE) as those biomarkers discovered in the last five years and, among previously validated biomarkers, also those applied in different ranges of doses or those determined in biological matrices which differ from matrices originally considered. We examined the results from the surveys carried out by the main Italian research units involved in biological monitoring, i.e. those from the Universities of Brescia, Milan, Naples, Padua, Parma, Pavia, Turin and Verona. The data were collected using a standardized model and included the following: type of element or organic compound, type of biomarker, analytical technique and method, their relationship with environmental monitoring data, their relationship with effect indicators or effects in general, improvement with respect to old biomarkers, reference values. Twenty two NBEs were identified: 14 elements and chemical compounds as such or as metabolites, 4 examples of mixtures, 3 of new matrices, one of speciation. Among the others, aspects such as interest in requiring NBE, quality assurance, availability, cost-benefit ratio were discussed. We conclude that development of this specific field of research appears to be a crucial point for future improvement in risk assessment and health surveillance procedures.

[Job as a risk factor for obesity... and the contrary]

BACKGROUND

Obesity constitutes a risk for several vascular, metabolic and neoplastic diseases. In industrialised countries, but more and more in developing countries too, the prevalence of obesity is increasing. Body Mass Index and circumference of the abdomen are the two simplest and most utilized methods of measuring the degree of obesity in an individual and of comparing selected groups with different ethnic, social, cultural and occupational features.

OBJECTIVES

The main aim of this article is to initiate a discussion on the possible contribution that the Occupational Health Physician can make to solving the problem of obesity, which is becoming more and more alarming in social terms. The working conditions favouring an increase in body weight and the negative effects that obesity has on various types of work are reported.

METHODS AND RESULTS

A critical review of the literature on obesity and overweight stresses that a low educational level, a low socio-economic status, lack of physical activity in leisure time and certain working conditions, together with the ready availability of food, are the main factors favouring increased prevalence of obesity. Certain jobs also contribute significantly to this problem. Automation and the use of machines/robots for very heavy work in industrialised countries have the "collateral effect" of favouring body weight increase due to low energy consumption. Jobs that are a source of stress, such as work on three rotating shifts, can cause metabolic disorders leading to an increased prevalence of obesity. Contrariwise, obesity renders the individual unfit for some jobs, in fact, an increased incidence of industrial accidents has been related to obesity.

CONCLUSIONS

The occupational health physicians engaged in surveillance of workers' health conditions can make a positive contribution to alleviating this problem by focusing their activity on the primary prevention of obesity and advising workers on how to maintain the right weight; otherwise, obese workers should be referred to appropriate medical centres.

Biological monitoring in occupational exposure to low levels of 1,3-butadiene

Exposure to 1,3-butadiene (BD), a probable carcinogen to humans, was investigated in two groups of subjects working in a petrochemical plant where BD is produced and used to prepare polymers: 42 occupationally exposed workers and 43 internal non-occupationally exposed controls. BD personal exposure was very low but significantly different in the two groups (median airborne BD 1.5 and 0.4 microg/m(3) in exposed and controls, respectively). Similarly, BD in blood and urine, but not in exhaled air, was higher in the exposed workers than in controls (blood BD 3.7 ng/l versus <1.8 ng/l, urinary BD 2.4 ng/l versus <1.0 ng/l). These three biomarkers correlated significantly with personal exposure ( 0.283 < or = Pearson's r < or = 0.383) and between them (0.780 < or = r < or = 0.896). Excretion of urinary mercapturic acids N-acetyl-S-(3,4-hydroxybutyl)-l-cysteine (MI), N-acetyl-S-(1-hydroxymethyl-2-propenyl)-l-cysteine and N-acetyl-S-(2-hydroxy-3-butenyl)-l-cysteine (MII), chromosomal aberrations (CA), and sister chromatid exchanges (SCE) in peripheral blood lymphocytes were not influenced by occupational exposure. Our results show that unmetabolised BD in biological fluids, and particularly urinary BD, represents the biomarker of choice for assessing occupational exposure to low airborne concentrations of BD.

Biological monitoring of occupational exposure to N,N-dimethylacetamide with identification of a new metabolite

AIMS

To study the concentration of N,N-dimethylacetamide (DMA) and its metabolite, N-methylacetamide (NMA), in urine of workers occupationally exposed to DMA in a factory producing synthetic acrylic fibres.

METHODS

During the first phase, 223 workers exposed to low environmental concentrations of DMA provided urine samples at the end of a work shift. High concentrations of the unmodified solvent and its metabolite were found in a group of workers whose job was to start up machinery. The second and third phases focused on conditions favouring high uptake of DMA.

RESULTS

The highest concentrations of unmodified solvent and NMA were found in the urine of workers recently engaged in starting up machinery. NMA in urine was 1.5-173.6 mg/g creatinine (median 20.5). In spite of the low environmental concentration, about 20% of the urine concentration of NMA was higher than 30 mg/g creatinine. Dermal absorption of DMA was high. A shower and a change of clothing at the end of the work shift, and washing away any solvent left on the skin, ensured that dermal absorption of DMA did not continue. This significantly reduced the NMA urinary concentration at values lower than 30 mg/g creatinine. In some urine samples, S-acetamidomethyl-mercapturic acid was identified by NMR analysis; this is probably a metabolite of N,N-dimethylacetamide--it has never before been identified in humans or animals.

CONCLUSIONS

Even at low environmental concentrations of DMA, dermal absorption can be considerable. Unmodified DMA and NMA concentrations in urine are good biomarkers for monitoring occupational exposure to the solvent.

Comparison of breath, blood and urine concentrations in the biomonitoring of environmental exposure to 1,3-butadiene, 2,5-dimethylfuran, and benzene

OBJECTIVES

To investigate and compare alveolar, blood, and urine concentrations of 1,3-butadiene, 2,5 dimethylfuran, and benzene, in non-occupational exposure to these products.

METHODS

Benzene, 2,5-dimethylfuran and 1,3-butadiene were measured in the breath, blood, and urine samples of 61 subjects living in small mountain villages. All 61 were regularly employed as forestry workers. Sampling was done during the long winter-season non-working period. Samples were collected after overnight rest and analysed by headspace and GC-mass spectrometry methods.

RESULTS

The median 1,3-butadiene level was 1.2 ng/l (range: <0.8-13.2 ng/l) in alveolar air, 2.2 ng/l (range: <0.5-50.2 ng/l) in blood, and 1.1 ng/l (range: <1-8.9 ng/l) in urine. The median benzene level was 5.7 ng/l (range: <1-24.9 ng/l) in alveolar air, 62.3 ng/l (range: 33.5-487.2 ng/l) in blood, and 63.4 ng/l (range: 25.8-1099.1 ng/l) in urine. The median 2,5-dimethylfuran level was 0.5 ng/l (range: <1-12.5 ng/l) in alveolar air, 2.5 ng/l (range: <5-372.9 ng/l) in blood, and 51.8 ng/l (range: <5-524.9 ng/l) in urine. In several cases, 2,5-dimethylfuran levels were below the detection limit in alveolar air and blood, especially in non-smokers. 1,3-Butadiene, 2,5-dimethylfuran and benzene levels were significantly higher in smokers than non-smokers in all biological media.

CONCLUSIONS

1,3-Butadiene and benzene, as ubiquitous pollutants, are detectable and quantifiable in human alveolar air, blood and urine. 2,5-Dimethylfuran, which is not a usual environmental pollutant, is almost always detectable in biological media, but only in smokers.

[Biological monitoring of occupational exposure to acrylonitrile]

Acrylonitrile (ACN) is a solvent widely used in industry especially as raw material in the manufacturing of acrylic fibres, clothes and domestic furniture. It is also used in manufacturing of resins (ACN-butadiene-styrene...) and for production of nitrilic elastomers. Some researchers proposed the biological monitoring of occupational exposure to ACN by measuring the solvent in the urine, but results were widely spread especially in relation to the analytical method used. This article reports the main aspects that can reduce the variability of results. We checked several ACN solutions in water and urine after heating at 90 degrees C for 1, 3, 5, 8 and 16 hours. Water solutions maintained their ACN concentration in all the checked conditions, while urine concentrations of ACN in urine deceased during the conditioning time until 80% of their initial concentration. The analysis of ACN in urine provided by workers potentially exposed to ACN and by control subjects gave median results of 1.9 and 2.0 micrograms/g creat, without any statistical difference. The results split in relation to the smoking habit showed a statistic difference: the median values of ACN were 1.7 and 4.7 micrograms/g creat, respectively among the 175 non-smokers and 57 smokers.

[Occupational exposure to methyl tert-butyl ether (MTBE) at an oil refinery]

Methyl tert-butyl ether (MTBE) is widely used as an additive to gasoline, to increase oxygen content and reduce tailpipe emission of carbon monoxide. Our research dealt with 37 refinery workers in order to measure their occupational exposure to MTBE during two different seasonal periods. They provided blood and urine samples before and after a work shift during which they wore an active charcoal sampler for solvents. All samples were analysed by a gas-chromatograph equipped with a mass spectrometer detector. The concentration in air of MTBE was very low (median: 25 micrograms/m3 in spring and 5 micrograms/m3 in autumn). The blood and urine concentrations of MTBE at the end of the work shift were higher than those found before the shift. The increment in biological samples confirmed a small intake of MTBE by refinery workers: the biological monitoring of occupational exposure to this solvent yielded reliable results. Blood and urinary concentrations of MTBE obtained from workers split in relation to their smoking habit did not give a statistic significance to say that cigarette smoke is not a confusion factor in monitoring exposure to MTBE.

Poor metabolization of n-hexane in Parkinson's disease

Although genomic screening studies have identified several genes associated with Parkinson's disease (PD), there is evidence that environmental factors are also involved in the pathogenesis of the disease and that hydrocarbon-solvents may be one of them. The genetic component is less evident in late-onset PD. To assess whether age and PD may affect the catabolism of the hydrocarbon n-hexane, a two-part study was performed. In the first part the urinary levels of its main metabolites, 2,5-hexanedione and 2,5-dimethylpyrroles, were measured in 108 patients and 108 healthy controls, matched by age and sex. Metabolite urinary excretion was significantly reduced in PD patients as compared with controls and was inversely related to age in both groups. In the second part the same comparison was made between 24 non-smoking and 10 smoking patients, matched to controls, after smoking of a hydrocarbon-rich cigarette. In these subjects also n-hexane and 2,5-hexanedione blood levels were measured. There was no appreciable difference in n-hexane blood levels between patients and controls in non-smokers, whereas there was a significant increase in patients over controls in smokers (p < 0.01). 2,5-hexanedione blood levels were significantly lower in patients than in healthy controls, both in non-smokers and in smokers, but the reduction was more pronounced in smokers (-46.3 % versus -10.7 %). The same was true for 2,5-hexanedione and 2,5-dimethylpyrrole urinary levels. This study suggests that aging and PD may be associated with a reduction in the capacity to eliminate the hydrocarbon n-hexane. This metabolic alteration may play a role in the pathogenesis of PD.