[Role of some psycho-physiological factors on driving safety]. / Ruolo di alcuni fattori psico-fisiologici sulla sicurezza alla guida.

Within a research project on the role played by human factors on road accidents, the aim of the present study is to evaluate, in young adults, the relationships between driver behaviour and personality factors as well as to assess the neuroendocrine correlates of psychological and behavioural factors investigated. Another aim is to estimate in what measure the performance levels are affected by demographic, psychological and chronobiological variables. It has been found a positive relation between highway code violations, extroversion trait of personality and Sensation Seeking scores, so confirming that this component of personality can affect risky behaviour. Furthermore the subjects more oriented to morningness chronotype were found to be prone to adopt safe driving behaviour. Regarding the relations of the neuroendocrine parameters and driving behaviour a positive correlation was observed between dopamine levels and frequency of driving violations while a negative relationship was found between adrenaline levels and frequency of driving errors. In conclusion the identification of psycho-physiological variables related to driving risky behaviour might be a useful instrument to design traffic safety programs tailored to high risk subjects.

Relation between psychoneuroendocrine profile in stressful conditions and antibodies to herpesvirus 6 and 7.

The aim of the present study is to evaluate whether the individual susceptibility to infectious disease is influenced by the psychological profile of cadets exposed to stressful events associated with military lifestyle in academy and if the neuroendocrine responses to stressful events is related with humoral immunity estimated by measuring antibody titres to human herpesvirus (HHV-6)7 (HHV-7) and to what extent it is influenced by personality traits. It has been observed that cadets with lower psychoaptitude scores (1-2) have a significant higher susceptibility to infectious disease (x2=7.95; p=0.019) compared to subjects with higher scores. A positive relationship between cortisol and antibody titers to HHV-6 (r=0.304; p=0.024) it has been found. It can be interesting to observe that antibody titers on HHV-6 are also related to psychoaptitude profile (r=0.239; p=0.044). The antibody titers to HHV-7 are negatively related to the 5 scales of BFQ and in particular with subdimension Co (cordiality) of BFQ (r=0.401; p=0.002). The survey carried out on over 1,500 cadets of the Military Academy of Modena shows that the susceptibility to infectious diseases during the first six months of admission to the Academy seem to be influenced by the psychoaptitudinal profile. The finding of a positive relationship between serum cortisol and antibody vs HHV-6 suggests that the impairment of the immune system linked to circulatory cortisol levels may induce a reactivation of a latent herpesvirus 6 with related increase of antibody titers.

Effects of chronic exposure to anaesthetic gases on some immune parameters.

A cross-sectional survey was carried out to evaluate the relation between occupational exposure to low levels of anaesthetic gases (nitrous oxide and isoflurane) and immune parameters. Fifty-one anaesthetists were recruited among different Services of Anaesthesiology and Reanimation. The control group consisted of non-exposed physicians, similar for gender, age, and job grade. Total number of lymphocytes, lymphocyte subpopulations and the natural killer (NK) cytotoxic activity were measured. Information on personal and professional characteristics and on short- and long-term exposure was collected. Percentages of T cells (CD3) decreased significantly in anaesthetists compared to controls, whereas numbers of NK cells (CD16+ CD3-) increased. After correction for confounders, short-term (last 2 weeks) exposure was associated with a decrease in percentages of total T and T helper (CD4) cells. Furthermore, T helper percentages were significantly reduced with increasing individual exposure score evaluated on the basis of working days and levels of anaesthetic gases in operating rooms. A significant X-ray-associated increase of numbers and percentages of NK cells was lastly observed. Despite limited present exposure to anaesthetic gases, a specific derangement in lymphocyte subpopulations, with T lymphocytes more affected than B, has been observed.

Mortality in a population with long-term exposure to inorganic selenium via drinking water.

We analyzed the 1986-1997 mortality in a cohort of 2065 residents of an Italian municipality which had been exposed to drinking water with a high content of inorganic selenium over a long period of time, and compared it with mortality in the remainder of the municipal population. Mortality from malignant neoplasms increased [standardized mortality ratio (SMR) 1.17, 95% confidence interval (CI) 0.96-1.42], mainly due to an excess mortality from melanoma and colorectal cancer in both sexes, kidney cancer in men, and lymphoid malignancies in women. Overall cardiovascular mortality changed little (SMR 1.05, 95% CI 0.89-1.23), despite the higher cerebrovascular mortality (SMR 1.43, 95% CI 1.03-1.93). Coronary disease mortality slightly decreased (SMR 0.87, 95% CI 0.63-1.16), due to a low mortality among women. We also noted an excess mortality from Parkinson's disease in men and from motor neuron disease in women. Evaluation of these findings is, however, hampered by the lack of information about potential lifestyle confounders, the fact that the exposure could only be characterized by a simple dichotomization, and the inconsistencies of most estimates between the two sexes.

Relation between immune variables and burnout in a sample of physicians.

OBJECTIVES: To evaluate in a group of physicians the relation between burnout, demographic or job characteristics, anxiety, and immune variables. METHODS: Seventy one physicians of all grades were recruited among different departments to a cross sectional survey. The Maslach burnout inventory, scales of emotional exhaustion, depersonalisation, and personal accomplishment, the trait scale of anxiety inventory (STAI-Y2), and a questionnaire on personal and professional characteristics were administered. The immune profile included quantitative (number (%) of lymphocytes and subsets) and functional (natural killer cytotoxicity) measures. RESULTS: With a model of stepwise multiple regression analysis, emotional exhaustion was significantly affected by both personal (marital, sex) and job characteristics (qualification, working activity), whereas only patient contact explained a portion of variation in depersonalisation. Furthermore, trait anxiety was found to predict the Maslach burnout inventory scores. After correction for potential confounders, physicians who scored high levels of personal accomplishment showed significantly higher numbers of total lymphocytes, T cells (CD3), T helper cells (CD4), and T suppressor cells (CD8) than those who scored low levels. No other correlation was found between burnout and immune variables. CONCLUSIONS: In our group of relatively young physicians a high degree of personal accomplishment was associated with an increase in the number of peripheral lymphocytes, particularly T subsets. The meaning of this is not clear, although it could be speculated that to evaluate oneself positively, particularly with regard to work with patients in the health services, might help to stimulate the immune system. By contrast, there is no evidence that to work hard, to feel tired from work, and to have a cynical reaction towards patient care is related to immunosuppression.

Reproductive outcomes in a population exposed long-term to inorganic selenium via drinking water.

Despite being an essential element in mammals and lower animals at very low doses, selenium is recognized as a teratogen and a growth-inhibiting substance in several animal species. Some inorganic selenium compounds have also been shown to be mutagenic and pro-oxidant: however, very little is known about their effects on human reproduction. Between 1972 and 1988, a few thousand residents in the municipality of Reggio Emilia, northern Italy, were accidentally exposed to drinking water with unusually high levels of inorganic selenium (selenate), range 7-9 microg/l, through a local public water supply system. We found no deleterious effect on overall body weight and length of newborns and stillborns delivered by 18 women previously exposed to high-selenium tapwater. Rates of spontaneous abortions, however, were increased slightly (RR = 1.73; 95% CI = 0.62-4.80), compared with rates among unexposed women from the same municipality. From 1980 through 1988 the prevalence of congenital malformations at birth among the exposed population was similar to that expected, but estimates were imprecise owing to small numbers. Results do not suggest marked effects on human reproduction from chronic exposure to selenate in drinking water at < 10 microg/l.

Learning impairment produced in rats by the cannabinoid agonist HU 210 in a water-maze task.

To ascertain whether the cannabinoid agonist HU 210 (25, 50, or 100 microg/kg, IP) influences rat spatial learning, water-maze performance was examined in the place (hidden platform)--and cue (visible platform)--versions of the Morris water maze. In addition, other unlearned behaviors were examined, namely, vocalization and wall hugging during the place task, and motor abilities during a motor test battery. The results obtained show that HU 210 at 50 or 100 microg/kg (once daily for 4 days, 60 min before a daily session) impaired learning in the place version but not in the cue one; wall hugging and enhanced vocalization were also displayed by the animals in the fourth session. Motor activity was compromised by the same treatment schedule. When the drug was discontinued, the effects produced by HU 210 at 50 microg/kg reversed in 3 days, while disruption of acquisition and vocalization caused by HU 210 at 100 microg/kg remained after 7 days' abstinence. Discussion centers on the possible specific cognitive mechanisms affected by the drug and on aspecific factors (i.e., anxiety-like state), which may contribute to the impairment of spatial learning.

Emotional stability, anxiety, and natural killer activity under examination stress.

This study was performed to evaluate the relation between a stable personality trait, a mood state and immune response to an examination stress. A self-reported measure of emotional stability (BFQ-ES scale) was obtained in a sample (n = 39) randomly selected from 277 cadets; this personality trait was also investigated by completing a neuroticism scale (Eysenck personality inventory) and a trait-anxiety scale (STAI). Natural killer (NK) cell activity was measured at baseline, long before the examination time and the examination day. The state-anxiety scale evaluated the response to the stressful stimulus. Taking subjects all together, the academic task did not result in significant modification over baseline in NK cell activity. Subjects were then divided into three groups based on emotional stability and state-anxiety scores: high emotional stability/low anxiety, medium, and low emotional stability/high anxiety. Examination stress induced significant increases in NK cell activity in the high emotional stability/low anxiety group, no effect in the medium group, and significant decreases in the low emotional stability/high anxiety group. The repeated-measure ANOVA revealed a significant interaction of group x period (baseline vs. examination) for both lytic units and percent cytolysis. The results did not change after introducing coffee and smoking habits as covariates. Our findings suggest that the state-anxiety acts in concert with a stable personality trait to modulate NK response in healthy subjects exposed to a psychological naturalistic stress. The relation between anxiety and poor immune control has been already described, whereas the ability of emotional stability to associate with an immunoenhancement has not yet reported. The peculiarity of our population, a very homogeneous and healthy group for life style and habits, can have highlighted the role of emotional stability, and may account for the difference with other studies.

[Evaluation of the risk of neuropsychological damage from lead exposure in childhood]. / Valutazione del rischio di danno neuropsicologico per esposizione al piombo nell'infanzia.

Potential neurotoxicity of lead in children has been explored in many recent epidemiological studies carried out all over the world. Within a multicentric European study, an investigation was carried out also in Italy on children living in an industrial area and characterised by a non steady-state exposure condition with higher exposure at the early stages of life. This peculiar feature allowed to observe interesting associations between neurobehavioural functions and the levels of Pb measured in teeth, but not in blood. Indeed, Pb in teeth was associated with the results of psychometric tests which evaluate the discriminant ability and the attention. Other associations, like those found between the intelligence quotient (IQ) scores and Pb in teeth disappeared after correction for the socioeconomical status of parents. In general, in children exposed to environmental Pb, more consistent associations were found with visual-motor integration and attention than with IQ measurements. In agreement with literature data from other countries, we suggest that the relevance of neurotoxic effects of Pb is limited, at least at the current exposure levels, but also that a threshold Pb level associated with no effect cannot be identified.

Inter-individual variability of benzene metabolism to trans,trans-muconic acid and its implications in the biological monitoring of occupational exposure.

Unmodified benzene (UBz) and trans,trans-muconic acid (t,t-MA) were measured in urine samples collected at the end of the first half-shift in 80 bus drivers from a large city in Northern Italy. Mean UBz was 1155 ng/l (S.D. = 494), range 85-1980 ng/l; these values roughly correspond to 10-1000 micrograms/m3 of benzene in air. Mean t,t-MA was 297 micrograms/g creatinine; the range was large (20-1295 micrograms/g creatinine), and the distribution of values was bimodal. At further analysis of t,t-MA data, two subgroups of 59 and 18 subjects were identified (3 outliers were excluded): mean values of the index were 108 (S.D. = 65) and 916 (S.D. = 264) micrograms/g creatinine respectively, and the values within each subgroup were normally distributed. The mean ratio between t,t-MA and UBz in the subgroups were 0.15 and 0.85, respectively; the difference was significant. The first subgroup was defined as 'poor t,t-MA metabolizers', the other as 'efficient t,t-MA metabolizers'. No inter-subgroup differences were observed regarding the main characteristics (age, dietary and smoking habits, etc.). As the parent compound of t,t-MA, trans,trans-muconaldehyde is myelotoxic, and its production has been implicated in benzene-induced leukemia. 'efficient' t,t-MA metabolizers may be at higher risk of developing benzene toxicity. If confirmed in further studies, the inter-individual variability rate of metabolizing benzene to t,t-MA may introduce some limitations in the application of this metabolite as an exposure index of low benzene exposure. Nevertheless, the t,t-MA/UBz ratio may be an important index of susceptibility to benzene toxicity.

Lead, cadmium, and selenium in the blood of patients with sporadic amyotrophic lateral sclerosis.

We determined whole blood lead and cadmium levels, and serum selenium levels in patients with sporadic amyotrophic lateral sclerosis and age- and sex-matched controls. Disability due to the disease directly correlated with lead levels, and there was a strong inverse correlation with selenium concentrations. Lead and selenium concentrations tended to be similar in the cases and controls, both in the study population as a whole and after the removal from the analysis of the patients with the highest degree of disability. In the patients with limited disability, cadmium concentrations were higher than in the controls. Our findings lend limited support to a possible involvement of cadmium, but not lead, in the etiology of sporadic amyotrophic lateral sclerosis, and strongly suggest that short-term indicators of exposure are inadequate to investigate the relationship between selenium and the disease.

Zinc and copper status and blood pressure.

In order to elucidate the relationships between Zn and Cu and blood pressure, the present case-control study was carried out. Zn and Cu status was evaluated in 60 subjects, pharmacologically untreated, affected by mild stable hypertension and in 60 normotensives matched for sex, age and smoking habits. Different markers of Zn and Cu status, including serum, erythrocyte and urine levels of the two trace elements and activities of some Zn- or Cu-dependent enzymes (alkaline phosphatase, lactic dehydrogenase, superoxide dismutase and lysyl oxidase) were evaluated. No significant difference between hypertensives and normotensives was observed in the mean levels of Zn and Cu as well as in Zn- or Cu-dependent enzymes, though higher levels of serum copper were associated with increased risk of hypertension. Interesting relationships between the biological parameters investigated were observed in the hypertensive subjects. Inverse correlations between blood pressures and serum Zn were observed. Furthermore, blood pressure was inversely related to lysyl oxidase activity. These findings give further support to the hypothesis that an imbalance of Zn and Cu bioavailability may be associated to hypertensive condition.