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Biomedical subjects

M Carrara

Publications and source records attributed to M Carrara.

At least 37 records · Page 2Linked to original sources
PubMed1995

[High-resolution computed tomography compared with the thoracic radiogram and respiratory function tests in assessing workers exposed to silica].

To compare the usefulness of high-resolution computed tomography (HRCT) and chest radiography in the functional evaluation of silica-exposed workers, 27 workers were submitted to posteroanterior and lateral chest radiographs, apex to base HRCT scans and pulmonary function tests. Two experienced readers studied plain films independently to assess small opacities profusion (ILO-UC, Geneva 1980): from 0/- to 3/+. HRCT grading and extent of silicotic nodules and associated emphysema were scored on a four-point scale. Inter-reader analysis showed better agreement for HRCT (K = 0.49) than chest radiography (K = 0.29). Poor agreement was observed between chest radiography and HRCT classes, particularly in the early stages of silicosis. No correlation was observed between chest radiography score and pulmonary function tests, while a significant correlation was observed between HRCT classes (grade and extent of the nodules) and FEV1, MEF50, MEF75, RV and FRC. In conclusion, HRCT exhibited better reproducibility and higher accuracy than chest radiography in identifying the absence of silicotic nodules and in depicting functionally important lesions. To this purpose, HRCT can be considered a useful support to conventional chest radiography.

Aged↗
PubMed1995

Oral slow-release theophylline does not prevent early and late asthmatic response to allergen in sensitized subjects.

In order to assess whether treatment with oral slow-release theophylline prevents early (EAR) and/or late (LAR) airway responses to allergen, we treated six asthmatic subjects with either placebo or oral theophylline (350 mg b.i.d.) for one week before specific bronchial provocation test (sBPT) with allergen, in a double-blind, cross-over, placebo-controlled study. All subjects had previously shown both EAR and LAR to allergen sBPT. On the day of sBPT, serum theophylline concentration was > 9 micrograms.ml-1 in all subjects treated with theophylline except one (mean 9.8 +/- 2.6 micrograms.ml-1). The total dose (TD) of inhaled allergen, and the provocative dose of allergen causing a 15% fall in forced expiratory volume in one second (PD15FEV1) during sBPT was mildly but significantly lower during theophylline-sBPT than during placebo-sBPT. Theophylline treatment reduced EAR (maximum FEV1 fall from baseline: 26.3 +/- 6.7 vs 32.2 +/- 9.5% after placebo treatment) but not LAR (19.5 +/- 6.5 vs 26.3 +/- 6.1%). A significant protection of LAR (a reduction in FEV1 fall after theophylline treatment 50% more than after placebo treatment) was observed in only 2 out of 6 subjects. Area under the curve was not significantly different after the two treatments. There was no relationship between serum theophylline levels and the degree of protection on EAR or LAR. The decrease in PD15FEV1 methacholine observed at the end of LAR was similar in the two treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Incorporation of [3H]ethanolamine into acetylcholine by a human cholinergic neuroblastoma clone.

Human neuroblastoma cholinergic LA-N-2 cells were used as an experimental model to test the possibility that the methylation of phosphoethanolamine (PEtn) to phosphocholine (PCho) and free choline (Cho) (Andriamampandry et al. 1989) could contribute to acetylcholine (AcCho) synthesis. LA-N-2 cells were incubated with [3H]Cho for 90 min and 22.7% of the radioactivity was present in PCho, 18.5% in free Cho and 4.8% as AcCho. The ratio of Cho/AcCho, however, was of about 1 after 16 hours of incubation. The incorporation of 10 microM [3H]ethanolamine (Etn) into MeEtn, PMeEtn, PMe2Etn and their corresponding phospholipids was reduced in cells incubated in medium containing 7.2 microM choline as compared to cells incubated in medium devoid of choline indicating that the lack of Cho from the incubation medium stimulated the conversion of PEtn to Cho water soluble derivatives. Incubation of LA-N-2 cells with [3H]Etn led to the labelling of [3H]AcCho. Cultures incubated in parallel with [3H]Cho showed that roughly 10% of [3H]AcCho obtained after 16 hrs of incubation with the Cho label derived from [3H]Etn. The synthesis of Cho and AcCho from Etn may be enhanced after cellular differentiation induced by the growth of the cells in the presence of retinoic acid (RA). The results indicate that the methylation of [3H]Etn and/or of [3H]PEtn may be used by cholinergic neurons as precursor for AcCho.

Acetylcholine↗
PubMed1994

The conversion of ethanolamine and of its metabolites to choline in human neuroblastoma clones: effect of differentiation induced by retinoic acid.

The sequential methylation of ethanolamine (Etn) or phosphorylethanolamine to the corresponding choline (Cho) derivatives was studied in both undifferentiated and retinoic acid (RA) differentiated human neuroblastoma clones LA-N-1 and LA-N-2. Conversion of Etn derivatives to the respective Cho metabolites was low in both cell types. However, after treatment of the cultures with ethanol or RA, the methylation of phosphoryl-Etn was stimulated while that of phosphatidyl-Etn was severely reduced in both cholinergic LA-N-2 and catecholaminergic LA-N-1 cells.

Biological Transport↗
PubMed1994

Prognosis of occupational asthma.

Several studies on the prognosis of occupational asthma have shown that a significant proportion of patients continue to experience asthmatic symptoms and nonspecific bronchial hyperresponsiveness after cessation of work. The determinants of this unfavourable prognosis of asthma are: long duration of exposure before the onset of asthma; long duration of symptoms before diagnosis; baseline airway obstruction; dual response after specific challenge test; and the persistence of markers of airway inflammation in bronchoalveolar lavage fluid and bronchial biopsy. The relevance of immunological markers in the outcome of occupational asthma has not yet been assessed. Further occupational exposure in sensitized subjects leads to persistence and sometimes to progressive deterioration of asthma, irrespective of the reduction of exposure to the specific sensitizer, and only the use of particular protective devices effectively prevents the progression of the disease. A long-term follow-up study of toluene diisocyanate (TDI)-induced asthma showed that the improvement in bronchial hyperresponsiveness to methacholine occurred in a small percentage of subjects and only a long time after work cessation. Bronchial sensitivity to TDI may disappear, but non-specific bronchial hyperresponsiveness often persists unchanged, suggesting a permanent deregulation of airway tone. Steroid treatment significantly reduces nonspecific bronchial hyperresponsiveness only when started immediately after diagnosis.

Adult↗
PubMed1994

Peak expiratory flow monitoring in diagnosis and management of occupational asthma.

The role of peak expiratory flow (PEF) monitoring in the diagnosis of occupational asthma has recently been assessed by several studies, which agree that this procedure should always be used to confirm the relationship between symptoms and occupational exposure. Some specific issues should be satisfied: a minimum number of four PEF measurements in a day; several weeks of monitoring in and out of work; and the presence of specific patterns of PEF changes. The sensitivity and specificity of PEF monitoring to detect occupational asthma, in comparison with the specific challenge test in the laboratory (the "gold standard") have been shown to be fairly high, although many authors believe that PEF monitoring cannot substitute for the specific challenge test. Limitations include: the low sensitivity of PEF to detect mild changes in airway calibre with respect to forced expiratory volume in one second (FEV1); the blunting effect of pharmacological treatment; the episodic and irregular exposure to the sensitizer in the workplace; and the compliance and honesty of the subject. Further studies are required to select the best indices of daily and day-to-day variability to be used in the evaluation of PEF changes between work and out-of-work periods.

Asthma↗
PubMed1993

Duration of preventive effect of inhaled salbutamol on early airway response to allergen in asthmatic subjects.

Salbutamol is known to effectively prevent early asthmatic response (EAR) after specific bronchial provocation test (sBPT) in asthmatic subjects, but the time-course of this protection is not known. In this study the effects of 200 micrograms salbutamol inhaled 2 h before sBPT were compared with 200 micrograms salbutamol inhaled 10 min before sBPT in eight asthmatic subjects sensitized to Phleum pratensis (PP) or Dermatophagoides pteronyssinus (DP). All subjects showed an EAR (% decrease in FEV1 from baseline value: 30.4 +/- 11%) in a preliminary sBPT performed with cumulated doses of extracts of PP or DP titrated in biological units (BU). Each subject performed, on two different days, in a random, double-blind, cross-over study, two puffs of placebo 2 h before sBPT and two puffs of salbutamol 10 min before sBPT (treatment A) or two puffs of salbutamol 2 h before sBPT and two puffs of placebo 10 min before sBPT (treatment B). Baseline FEV1 were similar in both tests. In treatment B, 10 min, 1 h and 2 h after salbutamol inhalation, FEV1 increased significantly with respect to placebo inhalation in treatment A. Ten minutes after salbutamol inhalation in treatment A, FEV1 became similar to that obtained 2 h after salbutamol inhalation and 10 min after placebo in treatment B. Allergen inhalation induced an EAR in only one out of eight subjects after treatment A, and five of the eight subjects after treatment B.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1993

Bronchial hyperresponsiveness and toluene diisocyanate. Long-term change in sensitized asthmatic subjects.

Long-term change in nonspecific and specific bronchial hyperresponsiveness was studied in 16 subjects with asthma induced by toluene diisocyanate (TDI). A significant positive correlation between months of follow-up and provocative dose inducing a 20 percent fall in FEV1 (PD20FEV1) methacholine was observed in 5 of 16 subjects. In 4 of these 5 subjects, a PD20FEV1 > 1 mg of methacholine was observed 30 to 48 months after the end of TDI exposure. In most subjects, nonspecific bronchial hyperresponsiveness did not change. Nine of 16 subjects became nonresponsive to TDI at follow-up examination, but only 3 of these showed a significant increase in PD20FEV1 methacholine. Seven subjects were still responsive to TDI. Recovery from TDI-induced asthma can occur and only after long-term work cessation. Nonspecific bronchial hyperresponsiveness to methacholine can persist even in the absence of bronchial hyperresponsiveness to TDI, suggesting permanent chronic damage to mechanisms controlling airway tone.

Adult↗
PubMed1991

Formamidines with antinociceptive and antiinflammatory activities.

Pursuing our investigations on 7-amino-2,3-polymethyleneindole derivatives, a set of 7-(dimethylaminomethylene)-amino-2,3-polymethyleneindoles, together with some other aryl or cycloalkyl substituted formamidines, were prepared and tested for analgesic and antiinflammatory activities. Several compounds resulted endowed with one or both of these activities; the indole derivatives 1 and 2 exhibited a good degree of both of them.

Amidines↗
PubMed1990

Influence of glycine on morphine-induced antinociception in mice.

The effects of glycine on morphine-induced antinociception were investigated in mice, using a cutaneous thermal test (hot-plate), a visceral chemical test (acetylcholine writhing test), and a locomotor activity test. When glycine (200 mg/kg p.o.) and morphine (5 mg/kg s.c.) were given together during the first 30 min, glycine first antagonized the morphine-induced antinociception then this was followed by a synergistic effect. The two-phase influence of glycine on morphine-induced antinociception may be due to the interaction of glycine with different receptors.

Acetylcholine↗
PubMed1989

Some new prazosin-like derivatives.

The preparation of a number of prazosin-like derivatives is reported. The new derivatives differ from the parent compound for the 2-side-chain which is represented by peculiar fragments of butyrophenone neuroleptics. The results of the pharmacological evaluation are also reported.

Animals↗
PubMed1988

Effect of L-carnitine on ethanol and acetate plasma levels after oral administration of ethanol in humans.

In a randomized double-blind, cross-over experiment, 0.5 g/kg of ethanol in the form of white wine and 3 g of L-carnitine by intravenous infusion were administered to 15 healthy volunteers. Ethanol and acetate plasma levels and the urine concentrations of acetylcarnitine were determined. Administration of ethanol induced a significant increase of both plasma ethanol and acetate, lasting 6-8 hr. The concomitant administration of carnitine resulted in a significant decrease of plasma acetate, whereas plasma ethanol levels remained unmodified. Urinary acetylcarnitine content significantly increased following administration of ethanol plus carnitine, but not when L-carnitine alone was administered. The resulting conclusion is that administered L-carnitine might trap excess acetyls derived both from free acetate, formed by ethanol oxidation, and from acetyl coenzyme A, accumulated as a result of the ethanol-induced decrease in the Krebs cycle flux.

Acetates↗
PubMed1988

Muscarinic cholinergic receptors in lung of developing rats.

The muscarin-specific radioligand 1-quinuclidinyl-[phenyl-4-3H]-benzilate was used to determine the development of muscarinic receptors in particulate membranes of rat lung. Postnatal development is associated with a decrease in the number of binding sites (Bmax). Bmax was 65.61 +/- 11.33 fmol/mg protein in 21-day-old rat fetuses and it decreased to 36.64 +/- 10.18 at postnatal day 1, 32.37 +/- 4.99 at day 7 and 16.15 +/- 4.13 fmol/mg protein at 2 months. Bmax at 2 months was significantly different from all the others (Dunnett's test). The dissociation constant Kd was 0.25 nM in 2-month-old animals and it did not undergo significant changes during development.

Aging↗