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Biomedical subjects

G Pisati

Publications and source records attributed to G Pisati.

At least 19 recordsLinked to original sources
PubMed2006

Rechallenging subjects with occupational asthma due to toluene diisocyanate (TDI), after long-term removal from exposure.

OBJECTIVES: Aims of this study were to define (1) whether toluene diisocyanate (TDI) bronchial hyper-responsiveness persists in subjects with occupational asthma after long-term cessation of exposure; (2) whether evolution of specific bronchial TDI sensitization and symptoms and functional abnormalities of asthma were coincident, and (3) the determinants at the time of diagnosis of patients' outcome. METHODS: Twenty-five nonatopic spray painters with occupational asthma due to TDI were re-examined 58 +/- 7 (46-73) months after removal from exposure. On both examinations, the severity of asthmatic symptoms and the need for antiasthma treatment over the past 12 months were graded and lung function tests, measurement of airway responsiveness to methacholine (PD(20)), circulating total IgE and TDI-HSA specific IgE, skin tests with common inhalant allergens and specific bronchial challenge with TDI were carried out. RESULTS: Seven subjects were still TDI-reactors and 18 lost reactivity to it. All persistent reactors had still asthma and their symptom score, medication score, FEV(1), PD(20) and serum IgE were unchanged between assessments. In the 18 subjects no longer responsive to TDI, 8 had still features of asthma: their symptom and medication score had improved significantly, but FEV(1), PD(20) and serum IgE had not significantly changed; the other ten patients no longer reactors to TDI were also asymptomatic and their PD(20) had become normal. The duration of symptomatic exposure to TDI was the only feature at diagnosis that differentiated patients with persistent TDI airway hyper-responsiveness and asthma from those who were no longer responsive to TDI but still asthmatic and those who were no longer responsive to TDI and no longer asthmatic (4 +/- 1.6; 2.1 +/- 0.8; 0.6 +/- 0.3 years, respectively; p < 0.001). CONCLUSION: our study demonstrates that airway sensitization to TDI and symptoms and functional airway abnormalities of asthma can persist for years after cessation of exposure and may have different outcome. If avoidance of the offending agent takes place within few months after the development of symptoms, remission of asthma and of TDI bronchial hyper-responsiveness can occur, whereas waiting for years makes it too late to cure asthma and, in the end, to reverse specific sensitization.

Adult↗
PubMed1999

Specific inhalation challenge with wheat flour in workers with suspected baker's asthma.

OBJECTIVE: The aim of this study was to evaluate the outcome of the specific inhalation challenge test (SIC) in 160 subjects with suspected baker's asthma and to assess its relation to total flour dust levels and to personal characteristics such as specific skin sensitisation, non-specific bronchial hyper-responsiveness (NSBH) and atopy. METHODS: We investigated the outcome of SIC tests performed with wheat flour in six Italian laboratories. For each subject, data was available regarding skin sensitisation to wheat flour, NSBH, atopy, forced expiratory volume at 1 s (FEV1) monitoring and airborne flour dust in the challenge chamber measured by the gravimetric method (total dust in mg/m(3)). RESULTS: The SIC test was positive for early asthma in 42 subjects (26%) and for late/dual asthma in 18 (11%). Positive outcome to SIC was significantly associated with NBSH (odds ratio, OR: 3.5, 95% CI: 1. 6-7.7) and skin sensitisation to wheat flour (OR: 3.1, 95% CI: 1.3-7. 0). Exposure level to wheat flour was less than or equal to 10 mg/m(3 )in 12% of individuals, ranged between 11 and 30 mg/m(3) in 43% and exceeded 30 mg/m(3) in 45%. The outcome of SIC was always negative among workers not skin sensitised to wheat flour and without NSBH and atopy. An increasing prevalence of positive SIC was observed among workers with one or more of the above-mentioned personal characteristics whose challenge exposure was greater than 10 mg/m(3) (P < 0.001). CONCLUSION: Procedures currently adopted for wheat flour dust exposure during SIC need to be better standardised in order to avoid excessive airborne dust exposure. Over-exposure seems to be of no use for the diagnosis and risks making the asthmatic reaction worse, particularly in patients who are both sensitised to wheat allergens and have NSBH and/or atopy.

Asthma↗
PubMed1994

Outcome of occupational asthma due to cobalt hypersensitivity.

We performed a follow-up study on nine subjects with occupational asthma due to cobalt hypersensitivity confirmed by a specific bronchial provocation test. Both at diagnosis and at the two follow-up visits (1 and 3 years after the diagnosis, respectively), we graded the severity of asthmatic symptoms and the need for antiasthma treatment and performed lung function tests, measurement of airways responsiveness to methacholine (PD15) and skin tests. The evolution of the disease was established on the basis of the increase or decrease in asthmatic symptoms and the requirements for medication, FEV1 and PD15. After cessation of exposure, two subjects recovered, five improved and one remained stable; the subject who carried on working in the same environment deteriorated. The improvement in symptoms, medication need and lung function occurred earlier and in a larger number of patients than the improvement in methacholine hyperreactivity. At follow-up, the inhalation test with cobalt was repeated on three subjects who had stopped exposure and were asymptomatic and again they had bronchoconstriction. Our data show that early diagnosis and early removal from exposure after the onset of asthma are important factors for a favourable evolution of the disease and that specific and non-specific bronchial hyperresponsiveness can persist even in asymptomatic subjects no longer exposed to the sensitizing agent.

Asthma↗
PubMed1994

Bronchial provocation testing in the diagnosis of occupational asthma due to latex surgical gloves.

In sensitized subjects, provocation tests to latex may induce severe systemic reactions and even anaphylactic shock. It is probable that part of the risk is due to the difficulty in grading the stimulating dose and in starting from very low levels of exposure. To identify the aetiological agent of work-related asthma in four nurses with previous allergic contact urticaria to latex surgical gloves dusted with cornstarch powder, we performed a specific bronchial provocation test study, based on exposure on three different days to nonpowdered latex surgical glove extract, powdered latex surgical glove extract and cornstarch powder extract, respectively. Extracts were nebulized in increasing concentrations in a 7 m3 challenge room, in the absence of the patients. The initial extract concentration was a tenfold dilution of the predetermined skin test end-point in the individual undergoing challenge, and the highest concentration was the undiluted extract. After exposure, the patients' forced expiratory volume in one second (FEV1) was monitored for 2 h. If FEV1 decreased by at least 15%, the next scheduled exposure was not carried out and FEV1 was monitored over a period of 24 h. Whereas nebulization of cornstarch powder extract caused no bronchial reaction in the patients, nebulization of nonpowdered latex surgical glove extract induced immediate bronchoconstriction in two subjects as an undiluted solution, and nebulization of powdered latex surgical glove extract induced immediate bronchoconstriction in all subjects at the 1:10 dilution. No systemic reaction was elicited by the bronchial provocation challenges. Our results demonstrate that airborne powder from latex gloves can be an inhalative occupational hazard.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Toluene diisocyanate induced asthma: outcome according to persistence or cessation of exposure.

Sixty patients with occupational asthma due to exposure to toluene diisocyanate (TDI) were re-evaluated, five years after the initial diagnosis had been confirmed by a specific bronchial provocation challenge. During both examinations the severity of asthmatic symptoms and the need for antiasthma treatment were graded and lung function tests, measurement of airway responsiveness to methacholine (PD15), and skin tests with common inhalant allergens were carried out. The evolution of the disease was established on the basis of the increase or decrease in asthmatic symptoms, requirements for medication, and FEV1 and PD15 methacholine between the two examinations. At follow up 17 patients (group A, 28.3%) had carried on working in the same environment after relocation to jobs with only occasional exposure to TDI; 15 of them used protective respiratory devices. The remaining 43 (group B, 71.7%) avoided further inhalation of TDI by moving to another sector. Group A showed a significant decrease in FEV1 and PD15 methacholine and significant increases in the severity of symptom score and requirement for medication; 13 subjects (76.5%) were worse, four (23.5%) were stable, and no one had recovered or improved. Group B showed significantly less severe symptoms and a threefold increase in PD15 methacholine; 12 subjects (28.2%) totally recovered, 10 (23.2%) improved, 16 (37.2%) were stable, and five (11.6%) were worse. In group B the duration of exposure to TDI and of symptoms before the initial diagnosis delineated the patients who recovered from those who did not improve; intermediate values in these features characterised the subjects who improved but did not recover. It is inferred that complete removal from exposure is the only effective way of preventing deterioration in patients with occupational asthma due to TDI. Early diagnosis and early removal from exposure after the onset of asthma are important factors for a favourable outcome of the disease.

Adult↗
PubMed1988

Cross-reaction between aromatic isocyanates (TDI and MDI): a specific bronchial provocation test study.

A study was performed on twenty-five workers exposed to polyurethane varnishes exclusively catalysed with TDI, who developed asthma to this substance. The aim of the study was to establish, using bronchial provocation tests, whether a cross-response to MDI exists. The results were positive but no definitive evidence has been reached because there was cross-response in only 48% of cases. It is interesting, however, that cross-responders did not predominate among the subjects with a late reaction to TDI (P = 0.0038), whereas cross-responders were in the majority among the subjects with a dual reaction to TDI (P = 0.0334). It is possible that the pattern of the asthmatic reaction to BPT with TDI influences the cross-reaction to other isocyanates.

Adult↗
PubMed1987

Subclinical inorganic mercury neuropathy: neurophysiological investigations in 17 occupationally exposed subjects.

17 workers in a thermometer factory exposed to mercury for periods ranging from 1 to 40 years all had high urine and blood mercury levels on undergoing electromyographic examination. All were clinically free from central and peripheral nervous symptoms. 88% had subclinical neuropathy, mainly distal and axonal. There was no correlation between severity of the neuropathy and blood and urine mercury levels or between severity of neuropathy and duration of exposure to mercury. The presence of a subclinical neuropathy in symptomless workers exposed to mercury is perhaps the most reliable index for the detection of the early toxic effects of mercury on the peripheral nerve fiber when it is probably still reversible.

Adult↗
PubMed1984

On ethylene oxide neurotoxicity: report of two cases of peripheral neuropathy.

Two cases of clinically and electromyographically proven ethylene oxide neuropathy occurred among 12 workers at the Lecco Hospital Sterilization Center. Cessation of exposure to the gas, which had lasted for two years, was followed by swift remission of the symptoms and complete normalisation of the EMG record at follow-up six months later. The paucity of published data on the subject may well mean that the real risk of ethylene oxide toxicity is being underrated.

Adult↗
PubMedDate not supplied

[Respiratory occupational allergies: the experience of the Hospital Operative Unit of Occupational Medicine in Lombardy from 1990 to 1998].

A retrospective study on occupational rhinitis and asthma diagnosed in 7 occupational health institutes in Lombardia (North-West Italy) was performed using a standardized card. 141 cases of rhinitis and 281 cases of asthma due to sensitization to occupational agents were analyzed and their clinical characteristics, aetiology, diagnostic methods and associated allergic diseases were determined. In this population the most frequent agents of occupational rhinitis were wheat flour and latex, whereas those of occupational asthma were latex and isocyanate. More than half of the subjects had more than one clinical manifestation of allergy. In 92 out of the 281 asthmatic patients rhinitis was the first clinical manifestation, particularly in subjects sensitized to high molecular weight substances, and preceded, asthma by 12 months as a mean. Specific bronchial provocation tests were useful for the diagnosis of asthma in 153 of the asthmatic patients and 45 of them had an isolated late bronchial reaction following the specific stimulus. At diagnosis 61 subjects (21.7%) had FEV1 < 80% of predicted; factors associated to ventilatory impairment were sensitization to high molecular weight substances, duration of exposure to the sensitizing agent, persistence of exposure after onset of symptoms.

Adolescent↗
PubMedDate not supplied

[Occupational allergic IgE-mediated disease from Boletus edulis: case report].

BACKGROUND: Fungal components can cause allergic symptoms either through inhalation, ingestion or contact. Allergic disease from occupational exposure to Boletus edulis (BE) has only seldom been reported. OBJECTIVES: Report on a female worker who developed respiratory and skin symptoms from occupational exposure to BE in selecting and packing dried mushrooms. She never had symptoms after eating mushrooms. METHODS: An environmental study was performed by personal air samplings and settled dust collection. The RAST-inhibition procedure was used to detect BE allergen potency in collected dust. The subject underwent clinical evaluation, spirometry, skin prick-tests, RAST methacoline and specific inhalation challenge with BE extract. A follow-up study was made 2, 4 and 8 months after the first evaluation and after cessation of exposure. RESULTS: BE allergens were found in the settled dust. Clinical examination showed eczema on the face and hands. The worker had hyper-eosinophilia, bronchial hyper-responsiveness to methacoline, no allergy to common inhalants and foods, positive prick-test and RAST for BE. The specific inhalation challenge induced broncho-constriction. At follow-up we observed a progressive clinical and functional improvement. CONCLUSIONS: Our data show that BE can induce cutaneous and respiratory symptoms from occupational exposure to dried mushroom dusts. The pathogenesis is an IgE-allergy. Our patient had no symptoms from ingestion, which supports the hypothesis that respiratory allergy is due to mushroom antigens that differ from those involved in food-related allergic reactions.

Adult↗