Biomedical subjects

G Maranelli

Publications and source records attributed to G Maranelli.

36 records · Page 2Linked to original sources

PubMed1985

Partition coefficients of some industrial aliphatic hydrocarbons (C5-C7) in blood and human tissues.

Saline/air, blood/air, olive oil/air, and tissue/air (lung, kidney, liver, brain, muscle, heart, and fat) partition coefficients were determined for nine aliphatic hydrocarbons: n-pentane, 2,2-dimethylbutane, 3-methylpentane, 2-methylpentane, methylcyclopentane, n-hexane, cyclohexane, 3-methylhexane, and n-heptane. Blood/air partition coefficients were found to range between 0.38 (n-pentane) and 1.9 (n-heptane) and the value of the tissue/air partition coefficients rose from n-pentane to n-heptane. The tissue/air partition coefficients were significantly correlated with the blood/air partition coefficients (r = 0.92-0.98). According to the slope of the regression lines, the mean solubility of the nine aliphatic hydrocarbons in the different tissues was higher than in blood by the factors: lung 1.4 (range 1.2-2.1) heart 3.9 (range 0.5-4.5), liver 5.6 (range 5.5-13.5), kidney 5.2 (range 1.6-5.8), brain 6.5 (range 5.8-10.7), muscle 7.6 (range 1.8-8.8), and fat 205 (range 104-254). The blood/air and olive oil/air partition coefficients were significantly correlated with the boiling points and the molecular weights of the aliphatic hydrocarbons studied.

Adipose Tissue↗

PubMedDate not supplied

ACTH 1-17 effects in chronic obstructive bronchitis.

The authors have tested the effectiveness of ACTH 1-17, administered in a single dose of 100 micrograms intramuscularly at 07(00) for 10 consecutive days, in 10 male patients suffering from chronic obstructive bronchitis with different ventilatory impairment. The subjects performed every 4 h (02(00), 06(00), 10(00), 14(00), 18(00), 22(00] for 14 consecutive days (3 days of wash-out and 10 days of treatment) spirometric tests with recording of 8 ventilatory parameters and of oral temperature. The day before and after treatment plasma cortisol levels were also determined 6 times a day. After the period of treatment 4 subjects improved, 4 remained stationary and 2 worsened as concerns the ventilatory functions, while 7 perceived a better general condition. The normal circadian synchronization of the respiratory function of the group, with acrophase in the afternoon, was maintained and the temperature rhythm was not influenced. The circadian rhythm of plasma cortisol showed a significant mesor reduction after treatment with a slight advance in acrophase indicating a partial inhibition of the hypothalamo-hypophyseal axis. The success of treatment was independent of the severity of the ventilatory impairment and the subjects showed different patterns of response both quantitatively (probably related to the dosage) and temporally (immediate or delayed). Hyperpigmentation of the skin owing to the intrinsic melanotropic activity of the peptide occurred in 2 subjects. As a side effect, weight increase was apparent in 3 subjects.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

[Guidelines for assessment and management of risks caused by benzene for workers at gas stations].

The European regulations classify gasoline as "carcinogenic agent" because of its content of benzene (> 0.1%). Consequently the preventive and protective actions towards the petrol station attendants prescribe, before all, the elimination of the agent or the reduction of the exposure and the risk to the minimum. Well known are currently a series of preventive measures able to produce appreciable reduction of the risk: reduction of the benzene content of gasoline, vapor recovery systems, self-areas or do-it-yourself, specific procedures for working. Exposure assessment is an essential step in order to establish the need for further preventive measure and to verify their efficacy. The exposure levels to gasoline of the petrol station attendants can be influenced by a variety of factors other than benzene air concentrations and therefore biological monitoring can give some sensible advantage in respect to air monitoring. Dosage of benzene in expired air, in urine, or in blood give a very good estimation of the exposure to benzene but they are not test largely practicable today, because analytical, economical, organizational reasons. Recent studies suggest that the dosage in urine of trans,trans muconic acid (ttMA) or phenil mercapturic acid can be useful biomarkers of recent exposure, even at low levels of exposure such as in filling stations. Exposure conditions to gasoline vapors in filling stations are rapidly changing thanks to some technological innovations and legal restrictions and the exposure levels are much below the occupational air standards, Toxicological and epidemiological data (although not yet conclusive at low doses) suggest to carry out however health and epidemiological surveillance programs for the working population. A program for the health surveillance and biological monitoring is here proposed: a clinical examination, integrated with haematological tests and biological monitoring tests, must be carried out in pre-employment and subsequently repeated yearly in the highest exposure conditions. When the exposure levels should decrease the examinations could be carried out every two years.

Benzene↗

PubMedDate not supplied

[The exposure to tobacco smoke of the employees of a telephone company].

Smoking habits were studied in a group of employees of a telephone company. The smokers were 34% of the subjects interviewed. The non-smokers said that they were bothered by other people smoking everywhere and also to a considerable extent at the workplace. Differences between smokers and non-smokers and between exposed and non-exposed non-smokers were studied by measuring expired CO and urinary cotinine. An expired CO concentration of 10 ppm discriminated between smokers and non-smokers. A mean urinary cotinine concentration of about 16 ng/mg was found in the exposed non-smokers, corresponding to the direct smoking of 1/10 of a cigarette per day. The search for the metabolic phenotype of destromethorphane, which was taken as an indicator of susceptibility to contract lung cancer due to IPA, showed that there were no differences between smokers and non-smokers since the rapid metabolizers, and therefore subjects potentially exposed to risk of lung cancer due to tobacco smoke, prevailed in both groups.

Adult↗

PubMedDate not supplied

[Exposure to silicon carbide fibers in the production of carborundum].

Recent reports have shown that not only silicon carbide dusts but also fibres are liberated into the working environment during the various phases of silicon carbide production (using Acheson furnaces), thus creating a further potential health hazard. An environmental hygiene survey was conducted in a silicon carbide production plant with the aim of quantifying airborne dusts and fibres. Although dust levels were below 50% of the TLV, high concentrations of fibres were observed (analyzed via optical microscopy using the criteria for asbestos fibres), which in some locations reached levels of 2000 fibres/litre with means (GM) between 100 and 780 fibres/litre according to department. These results are assessed in the light of the growing interest of researchers in the experimental effects of silicon carbide fibres.

Carbon↗

PubMedDate not supplied

[The biological levels of chloroform in the general population].

The paper reports the results of determination, via gas chromatography and mass spectrometry, of chloroform in expired air, blood and urine of a group of non-occupationally exposed blood donors. Chloroform concentrations were also measured for each subject in the air of the environment where samples were taken.

Adult↗

PubMedDate not supplied

[The prospects for the appearance of pleural mesothelioma in Italy].

The mortality data of Italian males and females due to malignant tumour of the pleura, collected over a period of 7 years, from 1976 to 1985, showed a continuous, rectilinear type, increase. The increase in the quantity of asbestos that was processed from 1945 to 1979 was also rectilinear. On the basis of the well known relationship between asbestos and mortality due to mesothelioma, an extremely high correlation coefficient was obtained between quantity of asbestos processed per year and number of deaths due to malignant tumour of the pleura 25 years later. Extrapolating to the year 2000 on the basis of this relationship, it can be foreseen that at that time the deaths due to malignant tumour of the pleura in Italy will be about 1200 per year. It is recommended to apply a correction factor to this figure in order to obtain the number of true cases of mesothelioma, which are probably about 70% of the deaths attributed to tumour of the pleura.

Asbestos↗

PubMedDate not supplied

Biological monitoring of fluctuating occupational exposures to styrene.

Nine workers occupationally exposed to styrene producing refrigerator lorries were analyzed. The styrene exposure was monitored 8 hours a day, for 5 days a week, for 1 week. We collected from workers a urine sample before and after each work shift. Moreover, alveolar air samples were obtained at the end of all work shifts. On Thursday afternoon and on Friday morning blood samples were taken from workers. The relationship between styrene exposure and biological data is reported and discussed. Alveolar, urinary and blood concentrations of styrene were comparable, suggesting similar kinetics. Biological styrene concentrations were significantly correlated with the mean daily environmental concentrations, but higher correlation coefficients were found with afternoon exposures. A narrow linear relationship between alveolar (Y) and urinary (X) styrene concentrations was found (Y = 0.359; r = 0.8579; n = 45; p less than 0.001). Urinary concentrations of mandelic acid (Y) confirmed a good relationship with the mean styrene exposure (X) (Y = 2.7 x +169; r = 0.4677 n = 45; p less than 0.01).

Air Pollutants, Occupational↗

PubMedDate not supplied

[Effects of cigarette smoking on blood and alveolar air levels of benzene].

Benzene was measured in blood and alveolar air of a group of 168 subjects, consisting of 34 chemical industry workers exposed to benzene and 134 definitely not occupationally exposed to benzene. A gas chromatographic method was used with mass spectrometry and cryogenic trap. The results of the biological measurements were compared with the environmental levels of benzene in the room where samples were taken and at the worksite during the previous day's shift. All environmental air samples showed measurable levels of benzene, which agrees with the observations of many authors, according to which benzene is a common pollutant also of the living and external environments. Benzene in blood measured on morning samples was correlated with the previous day's exposure. In the group of non-exposed, both blood and alveolar concentrations of benzene were significantly higher in the 68 smokers than in the 66 non-smokers and the biological levels of benzene were inversely correlated with the time that had elapsed since the last cigarette smoked. In the chemical workers, the high biological levels of benzene due to occupational exposure largely exceeded the variations in concentration due to cigarette smoking and cancelled out the differences between smokers and non-smokers. It can therefore be assumed that smoking was not influential and did not interfere with the interpretation of the results in the occupationally exposed workers. Lastly, cigarette smoking, as a cyclical and additional factors of exposure, seems to be responsible for the disturbance in the relationships between biological benzene levels and ubiquitous environmental pollution, a relationship that was only observable in non-smoking subjects not occupationally exposed, but not in the group of smokers.

Benzene↗

PubMedDate not supplied

[Pesticide immunotoxicity].

Pesticides have been reported as altering immune functions in animals and man. The authors review published data from which it emerges that pesticide exposure is often associated with depressed humoral and cellular responses in mammals. The immunomodulating effects are affected by the route of administration and can also occur without general toxic effects, with a clear dose-effect correlation and for different dose levels. Immunotoxicity has also been investigated in workers occupationally exposed to pesticides: many kinds of effects are described, since many immunotoxicants have multiple effects on immune functions but the authors emphasize the importance of further studies carried out in workplace situations where exposure levels can be more accurately measured.

Animals↗

PubMedDate not supplied