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Biomedical subjects

G Gilli

Publications and source records attributed to G Gilli.

At least 19 recordsLinked to original sources
PubMed1992

Geographical and temporal patterns of air-borne and personal 1,1,1-trichloroethane exposure in Piedmont region (Italy).

During the summer of 1989 and the winter 1989-1990, we initiated measurements of 1,1,1-trichloroethane concentrations in indoor, outdoor, and 'personal' air, in urban and rural sites. In the Piedmont region (North-Western Italy) we have carried out an atmospheric monitoring study: in the centre of Turin city (urban site), in Cuorgnè (rural site), and in Banchetta (remote site). First results confirm a higher winter contamination (11.67 vs. 2.79 micrograms/m3) and a higher contamination at the urban site, compared to rural and remote sites. Excluding Cuorgnè in the summer, all indoor/outdoor ratios are greater than 1 and, in all cases, the 'personal' air shows higher 1,1,1-trichloroethane levels than indoor and outdoor air. In Turin the relationships between winter and summer all show a higher winter contamination, while, in Cuorgnè no differences are proven.

Air Pollutants↗
PubMed1991

Sympathetic and vagal influences on rate-dependent changes of QT interval in healthy subjects.

Dependence of QT interval duration on cardiac heart rate has been well established and is considered to be an intrinsic property of ventricular myocardium. Conclusive results of autonomic influences on such phenomena are lacking. To evaluate whether rate-dependent changes of QT interval are conditioned by the autonomic nervous system, 28 normal subjects with no heart disease and a normal QT interval were electrophysiologically assessed. The QT interval was calculated at 6 paced cycle lengths (600, 540, 500, 460, 430 and 400 ms) during the basal state, and after beta blockade (propranolol 0.2 mg/kg) and autonomic blockade (propranolol plus atropine 0.04 mg/kg). Because of atrioventricular nodal conduction limits, intrapatient cross-comparisons were performed in 10 subjects (aged 42 +/- 15 years). Single regression lines, evaluated in each subject, showing correlation between pacing cycle length and QT duration at each of the 3 states were analyzed. The mean slope observed after autonomic blockade (b = 0.10 +/- 0.04) was significantly lower than that seen during the basal state (b = 0.22 +/- 0.12, p less than 0.05) and after beta blockade (b = 0.23 +/- 0.08, p less than 0.05); nonsignificant differences were found between slopes during the basal state and after beta blockade. Results showed that vagal tone increased intrinsic dependence of QT at increasing cycle length, whereas sympathetic tone did not seem to interfere significantly. Since (in each subject) beta blockade was performed--or achieved--before atropine administration, the vagal influences are likely to be directly exerted on the ventricular electrophysiologic substrate.

Adult↗
PubMed1991

Receptor binding at two different temperatures to discriminate agonist and antagonist behaviour of adenosine A1 receptor ligands in rat brain.

The inhibitory binding constants, Ki, at the adenosine A1 receptor in rat brain have been measured at 0 and 25 degrees C for 25 typical ligands. The Ki ratios at the two temperatures are greater and smaller than unity for adenosine agonists and xanthine antagonists, respectively. These results suggest that two-temperature measurements of in-vitro Ki constants represent a simple method of discriminating between in-vivo agonistic and antagonistic behaviour of A1 adenosine receptor ligands.

Adenosine↗
PubMed1991

Coagulation disorders and tumor markers in the diagnosis of pancreatic cancer.

Twenty patients (42-80 years old of whom 9 women) affected by instrumentally ascertained pancreatic cancer (7 cases were operated on) were studied. In all of them the following coagulation indices (fibrinopeptide A, FpA; beta-thromboglobulin, BTG; platelet factor IV, PF4; fibrinogen degradation products, XDP) and tumor markers (gastrointestinal cancer associated antigen, GICA; tissue polypeptide antigen, TPA; carcinoembryonic antigen, CEA; alpha-fetoprotein, or AFP) were assessed at the time of diagnosis, and 10 and 30 days after diagnosis, to test whether and which of the above parameters are more sensitive for entertaining the underlying affection. In both operated and nonoperated patients FpA was shown to be the most sensitive index. Lesser sensitivity was shown by XDP, GICA, and BTG. AFP proved to be quite useless as its serum levels constantly fell within the normal range.

Adult↗
PubMed1991

[Production of mutagenic compounds during the water purification treatment of surface water].

In the last years many studies have reported the presence of mutagenic/carcinogenic compounds in treated waters. These substances can be present in raw water, but are also produced during drinking water purification. Mutagens are formed as by-products of chemical reactions between oxidants/disinfectants used in treatments and organic load of the raw water (humic and fulvic acids). The aim of this study was to evaluate the production of mutagenic substances during the main phases of the Po river water treatment ("PO3" plant) in Turin. Water samples (50 litres), collected from February 1989 to August 1990, were concentrated with XAD-2/XAD-8 resins mixture. Extracts were tested for mutagenicity at different doses (1, 2.5, 5 and 10 litres) by Ames Salmonella assay, using TA 100 and TA 98 strains, without microsome fraction (S9). Raw water was rarely mutagenic while, in particular at the highest doses (5 and 10 litres), sometimes showed toxic effect. After ozonation treatment only few samples were mutagenic with TA 100 strain, while 43% of the samples were mutagenic with TA 98. The following treatment of clariflocculation and chlorination with NaClO produced mutagens in 95% of the samples assayed with TA 100 and in 85% of the samples assayed with TA 98. The next GAC/sand filtration step seems to reduce the mutagenic load produced in the previous phases. Finally, drinking water after chlorination with ClO2 showed weak mutagenicity at 1 litre dose (26% and 21% of positive samples with TA 100 and TA 98 respectively) and this effect increased at the higher dosages.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinogenicity Tests↗
PubMed1990

An overview of atmospheric pollution in Italy before the use of new gasoline.

In 1991 an Italian law will impose a lead reduction in gasoline from 0.4 to 0 g/l. In the present paper we show the actual level (1988) of contamination in Turin city air, in relationship to: lead, some Volatile Halogenated Hydrocarbon and carbonyls that are also bound (directly or indirectly) to emissions from automobiles filled with leaded gasoline. The results confirm the presence in atmosphere of some important "risk factors" for public health that could be substituted with some other ones.

Air Pollution↗
PubMed1990

Normal phase HPLC as a model system of specific benzodiazepine-receptor binding.

The hypothesis that benzodiazepines interact with their receptors in the CNS via hydrogen bonding mediated by the carbonyl and imine groups has been studied by correlating a physicochemical parameter affected by hydrogen bonds potentially accepted or donated by benzodiazepines with their binding constants to synaptosomal rat brain membranes. The reference physicochemical system chosen was normal phase high-performance liquid chromatography on mu-Bondapack NH2 (propylamine groups chemically bonded to porous silica) eluted with mixtures of n-hexane and 2-propanol. A strong correlation has been found for binding of the implicated groups to the column and to the receptor.

1-Propanol↗
PubMed1989

Use of leaded gasoline and volatile halogenated hydrocarbon emission from automotive exhaust.

The presence of volatile halogenated hydrocarbons (VHH) in the atmosphere of the urban areas of Piedmont and its possible correlation with traffic has been studied. Automotive exhausts of leaded and unleaded gasoline were tested, according to the "European Cycle" of the EEC guidlines N.C. 181/89, 7/9/1982, for the presence of seven VHH. The results show that VHH are produced in concentrations roughly proportional to the number of kilometres covered by each car. Cars filled with unleaded gasoline were substantially free of VHH. Thus, some of the VHH found in the atmosphere may arise from automotive (leaded petrol) exhausts.

Air Pollutants↗
PubMed1988

Temperature dependence of the binding of mu, delta and kappa agonists to the opiate receptors in guinea-pig brain.

Membrane preparations from guinea-pig brain were used to study the effects of temperature on the interaction of [3H][D-Ala2-MePhe-Gly-ol5] (DAGO), a selective mu agonist, [3H][D-Ala2,D-Leu5]enkephalin (DADLE), a nearly selective delta agonist and (+/-)[3H]ethylketazocine (EKC), a selective kappa agonist when binding was measured in the presence of an excess of DAGO and DADLE. Binding was endothermic (delta H0 = 10-17 kJ mol-1) and thus driven by the large increase in entropy (delta S0 = 200-230 J mol-1 K-1) for all ligands under examination. Van't Hoff plot for DAGO and DADLE showed a breakdown beyond 303 K which could have been due to lower in vitro stability of the proteins to conformational changes in the receptor proteins and/or to phase changes in the membranes. The present results do not agree with the hypothesis that agonist binding is associated with very small or negative delta S0 (in opposition to antagonists) in view of the information transfer involved (the biological effect).

Animals↗
PubMed1988

Relationship between atmospheric lead concentration and blood lead level in Turin (Italy).

On July 1, 1981 the Italian government received and implemented an E.E.C. directive dated 1978 calling for the reduction of lead in fuels from 0.6 to 0.4 g/L. The effectiveness of this legislative measure is evaluated here by comparison of data on atmospheric lead levels in the city of Turin, and blood lead levels in A.V.I.S. (Italian Association of Blood Donors) donors in Turin and the countryside (control group), before (1977) and after (1986, 1987) the enforcement of the law. The results show that the implementation of the law has contributed to a decrease in the atmospheric lead levels. The analysis of blood lead concentration revealed an evident biological response to this environmental change: there was a decrease in blood lead level between 1977 and 1987, in both the countryside (control group) and, to a lesser extent, in the city.

Adult↗
PubMed1987

Fanconi-Bickel syndrome.

Clinical, biochemical, functional and morphological data are presented in nine infants, children and adults, with Fanconi-Bickel syndrome. Long-term follow-up studies show severe growth retardation, partly compensated for by late onset of puberty. Glomerular filtration rate is normal or slightly decreased. Renal tubular dysfunction is characterized by a specific pattern of impaired proximal tubular transport mechanisms, with marked impairment of glucose transport. The utilization of glucose and galactose is defective, whereas fructose metabolism seems to be normal. Glycogenosis of the liver may be an epiphenomenon. Glycogen accumulation in the kidney is limited to the proximal tubule, with maximal levels in the straight part. The Fanconi-Bickel syndrome is a defined clinical entity which is distinguished from other inherited metabolic diseases by complex defects of renal tubular transport and other forms of glycogenosis.

Adolescent↗
PubMed1987

"High-dose" calcitriol for control of renal osteodystrophy in children on CAPD.

High doses of calcitriol were used prospectively for 11 to 29 months to raise serum calcium levels in an effort to control renal osteodystrophy in 16 children undergoing CAPD. Serum Ca, P, iPTH and alkaline phosphatase were measured monthly; hand radiographs were obtained every six months, and a semiquantitative score of bone abnormalities was evaluated by two independent observers. During the study, serum Ca increased from 9.9 +/- 0.9 to 11.0 +/- 0.6 mg/dl (P less than 0.001); serum iPTH decreased by 113 +/- 131 microliter Eq/ml (P less than 0.005); serum P was unchanged; and serum alkaline phosphatase fell by 33 +/- 46% (P less than 0.02), 530 +/- 397 to 204 +/- 551 IU/liter. The radiographic score fell from 4.8 +/- 4.6 to 0.9 +/- 1.2 (P less than 0.005). The average and maximal doses of calcitriol were 0.61 +/- 0.37 and 0.95 +/- 0.56 microgram/day or 28 +/- 18 and 46 +/- 28 ng/kg body wt/day, respectively. Transient and asymptomatic hypercalcemia occurred in nine patients and two patients had reversible conjunctivitis in association with the hypercalcemia. Thus, "high dose" calcitriol prevented or controlled progression of hyperparathyroid bone disease in most pediatric CAPD patients. The failure to suppress PTH or reverse secondary hyperparathyroidism until the serum Ca rose to 10.5 to 11.0 mg/dl could reflect an increase in the "set point" for PTH suppression by serum calcium in many uremic children.

Adolescent↗
PubMed1987

Stereochemical features controlling binding and intrinsic activity properties of benzodiazepine-receptor ligands.

Benzodiazepine-receptor ligands belong to several different chemical classes. All of them bind to the receptor but display a variety of biological effects ranging from agonist to inverse agonist to antagonist. The properties of the most representative compounds for each class are briefly reviewed as concerns their receptor binding affinities, gamma-aminobutyric acid ratios, photoaffinity labeling ratios, and pharmacological properties. Their geometries, as obtained by X-ray crystallography, are discussed and missing crystal and molecular structures of two of them (zopiclone and CL 218-872) are reported. Binding and intrinsic activity properties of series of benzodiazepines and beta-carbolines are extensively analyzed and correlated with their molecular structures. A general stereochemical model accounting for both binding abilities and kinds of biochemical and pharmacological activities for all benzodiazepine-receptor ligands is proposed. This is based on the assumption of a rather diffuse and substantially planar recognition site where the main drug-receptor interactions are mediated by the drug carbonylic or iminic groups via hydrogen bonding and the observed differences in pharmacological profiles are accounted for by the different localization of the different ligands inside this unique binding site.

Animals↗