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Biomedical subjects

A Prevost

Publications and source records attributed to A Prevost.

At least 19 recordsLinked to original sources
PubMed1998

Prevalence of respiratory symptoms and increased specific IgE levels in West-African workers exposed to isocyanates.

Respiratory symptoms and immunological effects from chronic exposure to isocyanates (toluene diisocyanate) were studied in a cross survey of workers from West African factories producing paints and polyurethane foam. A questionnaire, a pulmonary function test, immunoglobulin E (IgE) levels, radioallergosorbent test (RAST) and an atmospheric sample to quantify isocyanate exposures were carried out in the workplace for each worker. Ninety-six workers, of whom 44 had occupational isocyanate-induced asthma, were included in the study. Twenty-four viral-infected subjects were excluded from the immunological study. Specific antibodies to isocyanates were detected in two of the symptomatic individuals. This low proportion appeared to be a common feature of this disease. The prevalence of isocyanate-induced asthma in a West African working population appears to be significant in the context of chronic human exposure, as current data are based on excessive acute exposure due to an accident as seen in India.

Adult↗
PubMed1998

Mechanisms of occupational asthma induced by isocyanates.

Isocyanates are some of the most important low molecular weight chemicals associated with occupational asthma. These compounds are often volatile and they are highly reactive on mucous membranes, especially the conjunctivae and respiratory tract. Despite numerous data derived from experimental and clinical investigations, there is no agreement concerning the real mechanisms involved in isocyanate-induced occupational asthma. In fact, the cause of occupational asthma is multifactorial. The aim of this paper is to review the involved physiological causes of isocyanate-induced asthma; the main mechanisms are immunological, pharmacological and/or irritative.

Asthma↗
PubMed1996

Sharing of four DR-beta sequence motifs between HLA-DRB1*1601 and DRB1*1101 correlates with frequent degenerate T-cell recognition of HA306-320 peptide complexed to these two molecules.

This paper shows that the seven HA306-320 specific T-cell clones isolated from one individual recognize the peptide complexed to both autologous HLA-DRB1*1101 and allogeneic HLA-DRB1*1601 (or DRB5*0201) molecules. For each T-cell clone, a single T-cell receptor (TCR) is involved in the recognition of these two different peptide-DR complexes as evidenced by cold target competition experiments. Yet, the seven T-cell clones express several different TCRs as judged by V beta-J beta usage and fine specificities. Furthermore, one representative clone has the same fine specificity for HA306-320 analogues mutated at epitopic residues irrespective of the use of DR1101 or DR1601 APC. These results suggest that structural differences between DRB1*1101 and DRB1*1601 (or DRB5*0201) do not dramatically influence the orientation of HA306-320 in the grooves such that most residues interacting with TCRs are conserved. In another individual, the same pattern of restriction, i.e. DR1101 + DR1601, was found for several HA306-320 specific clones. Two additional patterns, DR1101 + DR0801 and DR1101 + DR0801 + DR1601, were identified. By comparing DR sequences the authors found that DRB1*1101 and DRB1*1601 share four important motifs, i.e. beta 85-86, beta 67-71, beta 57 and beta 28-31 supposed to line three distinct HLA-DR pockets. Three of these motifs are also shared with DRB1*0801. All the results further support that the motif similarities allow the peptide to adopt very similar orientations in the cross-reacting DR molecules.

Amino Acid Sequence↗
PubMed1996

[Value of the systematic uterine Doppler in the primiparous woman. A series of 315 cases].

OBJECTIVE: This retrospective study was designed to assess the screening of pre-eclampsia (PE) and intra-uterine growth retardation (IUGR) by uteroplacental doppler scan in a population of primiparous, selected in a hospital having 700 deliveries each year. STUDY DESIGN: We studied, a consecutive series of 315 primiparous women at 19 weeks (gestational age) screened by pulsed Doppler of uterine artery. Group A (normal uterine artery Doppler) was compared with group B (pathological uterine artery Doppler) for pregnancy-induced hypertension, preeclampsia and intra-uterine growth retardation (chi 2 test and Fisher test). RESULTS: Group B included 50 patients (15%). They had more hypertensive pathologies (24%) (p < 0.001) and IUGR (20%) (p < 0.005) were more frequent than the group A (265 patients: 85%) which had only 7.2% and 8.2% respectively. In this study, the sensitivity of uterine artery Doppler was 34.3%, the specificity was 88.5%, the positive predictive value was 42%, the negative predictive value was 84.9% for all hypertensive disorders. CONCLUSION: The contribution of this examination is doubtful in a low risk population where the prevalence of complications is low and the VPP is about 10 to 14% for preeclampsia. On the other hand, test predictivity reaches 50% for all dysgravidic disorders.

Arteries↗
PubMed1996

[Ventricular late potentials and sleep apnea syndromes].

This prospective study in 37 patients evaluated the prevalence of ventricular late potentials in sleep apnea syndrome, a condition associated with an increased risk of ventricular rhythm disorders and sudden death. A comparative analysis was conducted among a group of patients considered free of coronary heart disease and admitted for suspected sleep apnea syndrome based on clinical symptoms and simple blood gas measurements. The prevalence of ventricular late potentials was 56% in the subgroup with and 14% in the subgroup without polygraphy evidence of apnea (F < 0.01). The analysis of clinical, respiratory, and echocardiographic findings in the apneic subgroup failed to detect any factors associated with the presence of ventricular late potentials. Only long-term follow-up studies involving invasive heart rhythm testing could define the prognostic significance of ventricular late potentials in sleep apnea syndrome. However, our data demonstrate that there is an association between ventricular late potentials and sleep apnea syndrome.

Adult↗
PubMed1995

Allergy to latex, avocado pear, and banana: evidence for a 30 kd antigen in immunoblotting.

Allergens of natural latex, latex gloves, avocado pear, and banana extracts were investigated by an immunoblotting technique in sera of patients experiencing associated latex and fruit allergies. Extracts were separated by sodium dodecyl-sulfate-polyacrylamide gel electrophoresis and electroblotted onto nitrocellulose. After incubation with patients' sera, IgE antibodies were revealed by a goat anti-human IgE alkaline-phosphatase conjugate. Seventeen serum samples from patients with well-documented latex allergy were studied. Among these patients, 10 demonstrated an allergy to avocado pear sometimes associated with banana. In sera from patients with latex and fruit allergy, prominent IgE binding was revealed at about 30 kd with latex and fruit extracts. Serum controls remained negative. Cross-inhibition of immunoblotting confirmed that this main allergen is linked to a common epitope present in latex and fruits. This must be related to clinical findings and previous observations of cross-reactivity.

Adult↗
PubMed1994

[Bronchial epidermoid carcinoma with unusual disclosure].

Dissemination has often occurred before the diagnosis of bronchopulmonary cancer. Pancreatic metastases are exceptional and are very rarely the revealing manifestation. The authors report a case of a tumour of the pancreas which led to the discover of an bronchogenic epidermoid carcinoma. The relationship between these two tumours lead to the proposed hypothesis of pancreatic metastasis of a bronchogenic carcinoma. Although this situation is rare, the preoperative work-up for bronchogenic carcinoma should include computed tomography of the pancreas if the abdominal echography does not allow complete visualization of the pancreas in cases with suggestive digestive disorders. If a tumour is observed in the pancreas, scan-guided needle biopsy should be performed to enable the histological examination.

Carcinoma, Bronchogenic↗
PubMed1983

[Exeresis in occipital neuralgia].

31 patients, suffering from an occipital neuralgia, were treated surgically by section of the n. occipitalis major or minor. The retrospective study of these cases extends over a period of one to nine years. In 26 patients (84%) a good result was achieved initially, and 16 patients (52%) are completely free of any complaint up to the present. In five patients (16%) no improvement has occurred. In two of these five patients an epipharyngeal cancer was discovered later; in one of the patients trigeminal neuralgia was established later on. Contrary to earlier published intradural rhizotomy this operation is simple and without risk (it is performed under local anaesthesia), and in long-standing, obstinate and tormenting cases very good results can thus be achieved. The unclear aetiology of the neuralgia was observed anatomically by the atypical course of the nerves. Other methods for the treatment of occipital neuralgia were not considered here.

Adult↗
PubMed1982

[Not Available].

Explore the source record for details and available documents.

Biological Evolution↗
PubMedDate not supplied

[Non-metastatic advanced non-small cell lung carcinoma: systemic high-dose brachytherapy following curative external radiotherapy].

PURPOSE: To analyse retrospectively the local control, overall survival and immediate and long-term tolerance after a radiotherapy delivered with a curative intent systematically including a high-dose rate brachytherapy. PATIENTS AND METHODS: From January 1993 to January 1995, 50 patients (45 males-five females, median age: 61) with non-small cell lung cancers, inoperable for tumour reasons, non-metastatic, were included in the protocol. Following external radiotherapy (55-65 Gy conventional fractionation), all the patients received high-dose rate brachytherapy delivering 14 to 24 Gy using fractions of 7 Gy. RESULTS: Immediate tolerance was good. Two months after the end of the treatment, five patients suffered from massive haemorrhages and three others experienced a mucosal necrosis (two tracheal sites). Tumour response was observed endoscopically in 88% of the cases (38/50) and was complete in 38%. Median survival of complete responders was 15 months. In the mean follow-up period of 24 months, five patients were still alive with no evidence of disease (median survival: 30 months). Most of the patients died from distant metastases (33/50: 66%). CONCLUSION: Systematic use of endoluminal high-dose rate brachytherapy in addition to external radiotherapy did not improve survival. The gain in the local control rate was counteracted by an increase in haemorrhages and mucosal necroses. Improving techniques and dosimetry, and combining different methods which have proved their efficiency, should result in improvements in survival. Quality of life would be part of the analysed parameters in any future study.

Adult↗
PubMedDate not supplied

Malignant pleural effusions treated with high dose intrapleural doxycycline: clinical efficacy and tolerance.

Chronic malignant pleural effusion may be treated by instillating products in the pleural space to induce pleurodesis. We used intrapleural doxycycline at doses greater than 2000 mg in 16 malignant pleural effusion (14 patients). Patient survival ranged from 1 day to 19.5 months. Mean drainage duration was 7.5 days (range, 5-10 days). Pain (moderate n=7; severe n=2) was the most frequent side-effect with hypotension (moderate n=3; severe n=1). Five cases were not evaluable at one month because of death during the month following treatment (n=3) or during treatment (n=2). At one month follow-up, success was defined as no pleural effusion (n=5), partial response as minimal effusion (n=4) and we considered that treatment had failed if pleural drainage was necessary (n=2). Five patients died within one month and 5 had more than 3 months survival (4 without recurrence).

Adult↗
PubMedDate not supplied

Long-term effect and tolerance of talc slurry for control of malignant pleural effusions.

Drainage of malignant pleural effusions (MPE) by thoracocenthesis and subsequent pleurodesis is an established means of symptomatic relief in terminally-ill patients, but the optimal therapy remains unclear. Among many sclerosing agent, talc is the most widely used, but its intrapleural administration and dosage have not been clearly determined. To assess the efficacy of using talc slurry with high dose (8 g) as a sclerosing agent instilled into the pleural space at the patient bedside, we carried out a study in 31 patients suffering from symptomatic MPE, followed until death or up to 1 year with radiographs. Patients were evaluated for immediate tolerance (31 patients), and for efficacy and long-term tolerance (27 patients) of the talc therapy. We have shown, that pleurodesis was satisfactory in 22/27 patients (81.4%). This result appeared comparable with other series. Moreover, we observed a long-lasting efficacy: within 6 months and within 12 months after talc instillations, 20/20 patients and 9/9 patients respectively were symphysed with efficacy. Complications related to talc (8 g) were rare and moderate (pain, fever). Taking into account some technical aspects of talc instillation for good performance of the therapy, we recommend this method as the optimal route of administration.

Adult↗