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Biomedical subjects

B Housset

Publications and source records attributed to B Housset.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Tobacco dependence: a short evaluation questionnaire].

Two hundred and forty-eight smokers were questioned in order to determine the relation between Fagerström's questionnaire--an indirect test of nicotine-dependence in 8 questions with an 11 points score--and the shorter, and quicker, 6 points score questionnaire of only 2 questions described by Heatherton. The relation was considered satisfactory with 67 percent sensitivity and 90 percent specificity. Discordance was observed in only 6 cases. A 5 to 6 points score on the simplified questionnaire reflects a strong tobacco-dependence and justifies an attempt to facilitate tobacco withdrawal by using a nicotine gum or stamp.

Adult↗
PubMed1992

Interactions between human immunodeficiency virus-1, hepatitis delta virus and hepatitis B virus infections in 260 chronic carriers of hepatitis B virus.

To evaluate the factors determining the severity of chronic hepatitis B virus infection and the interactions of human immunodeficiency virus and hepatitis delta virus infections, we retrospectively analyzed 260 patients, 146 of whom were followed for a mean of 31.4 +/- 1.8 mo. Human immunodeficiency virus, hepatitis B virus, and hepatitis delta virus status and aminotransferase activities, histological activity index, alcohol consumption and the prevalence of cirrhosis were investigated. The patients included 54 homosexuals, 19 parenteral drug abusers and 187 subjects with other or unidentified risk factors for exposure to hepatitis B virus. Thirty-five patients (13%) were positive for antibody to human immunodeficiency virus; 27 were homosexual and 8 were drug abusers. The mean aminotransferase activities, histological activity index and the prevalence of cirrhosis were similar in the human immunodeficiency virus-positive and human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-negative subgroups. Actuarial survival was significantly lower in the human immunodeficiency virus-positive group than in the human immunodeficiency virus-negative subjects (p = 0.004); the cause of death was clearly related to liver failure in four of the five human immunodeficiency virus-positive patients and two of the six human immunodeficiency virus-negative subjects who died. To evaluate the factors determining the severity of liver disease, we compared homogeneous subgroups of subjects. Among the homosexual patients, the prevalence of HBeAg and hepatitis B virus DNA, aminotransferase activities and the histological activity index did not differ according to human immunodeficiency virus antibody status.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1992

Modulation of arachidonic acid metabolism and cyclic AMP content of human alveolar macrophages.

The exposure of human alveolar macrophages to inflammatory mediators such as PAF (1 microM), fMLP (1 microM) or the calcium ionophore A23187 (1 microM) induced a rapid decrease in their intracellular concentration of cAMP. Inhibition of TXA2 synthesis by the specific thromboxane synthase inhibitor ridogrel (1-10 microM) or by non-specific inhibitors as indomethacin (1-10 microM), the cyclooxygenase inhibitor, or BW A4C (1-10 microM), the 5-lipoxygenase inhibitor, partially prevented the decrease in cAMP induced by the different inflammatory stimuli. Evidence for an indirect control of cAMP levels in human alveolar macrophages by inflammatory mediators through the production of arachidonic acid derivatives from the cyclooxygenase pathway is supported by this study.

Adult↗
PubMed1992

[The diagnostic contribution of complementary tests].

The increasing number of complementary examinations in pneumology often makes it difficult to choose the appropriate tests for optimal investigation. After specifying the conditions in which reference values are established, the authors discuss the general principles of decisional analysis, i.e. sensitivity and specificity, probability ratios, the role of the disease prevalence in interpreting results (Bayes' theorem) and the odds ratio. Practical applications of these principles with regard to diagnosis and therapy in pneumology are also discussed.

Decision Support Techniques↗
PubMed1991

Decreased oxyhemoglobin affinity in patients with sleep apnea syndrome.

Oxyhemogloblin affinity (P50 at pH 7.4, PaCO2 = 40 mm Hg, temperature = 37 degrees C) and 2,3-DPG concentration were assessed in 15 nonsmokers (14 men and one woman 46 to 63 yr of age) with sleep apnea syndrome (SAS) and in 10 normal subjects (eight men and two women 22 to 48 yr of age). In patients with SAS, mean nocturnal apnea index was 46 +/- 20/h, and mean nocturnal SO2 was 86 +/- 6% versus 94.6 +/- 1.8% during the daytime. Daytime mean P50 of the patients was 28.5 +/- 1.2 mm Hg versus 27.1 +/- 0.3 mm Hg in the normal subjects (p less than 0.05). Daytime mean 2.3-DPG was 1.23 +/- 0.25 moles DPG/mole hemoglobin versus 0.80 +/- 0.15 (p less than 0.05). Significant correlations were found in patients between P50 and mean nocturnal SO2 (r = -0.62, p less than 0.01) and between P50 and 2,3-DPG (r = 0.68, p less than 0.01). The measurements were repeated in five patients after surgical or positive-pressure treatment. P50 and 2,3-DPG both decreased and returned to normal values. In conclusion, the oxyhemoglobin dissociation curve is shifted to the right in patients with SAS and there is an increase in 2,3-DPG. These could be protective mechanisms against the development of polycythemia, pulmonary hypertension, and cor pulmonale.

2,3-Diphosphoglycerate↗
PubMed1991

Toxic effects of oxygen on cultured alveolar epithelial cells, lung fibroblasts and alveolar macrophages.

Exposure to hyperoxia results in endothelial necrosis followed by type II cell proliferation. This suggests that type II cells are resistant to hyperoxia. Oxygen-induced lung injury may result from an overproduction of oxygen metabolites normally scavenged by antioxidants such as superoxide dismutase (SOD), glutathione peroxidase, catalase and reduced glutathione (GSH). Therefore, resistance of type II cells to hyperoxia may be linked to high antioxidant activities. To test this hypothesis we compared in vitro the effects of a 24 h exposure period to 95% O2 on cultured type II cells, lung fibroblasts and alveolar macrophages isolated from rats. We show that type II cells, when compared with other cell types, are highly sensitive to hyperoxia as shown by increased lactate dehydrogenase (LDH) release, decreased deoxyribose nucleic acid (DNA) and protein content of Petri dishes and decreased thymidine incorporation into DNA. Synthesis of dipalmitoylphosphatidylcholine was also significantly reduced. Antioxidant enzyme activities as well as glutathione content were not higher in type II cells than in other cell types. However, hyperoxia results in a decreased SOD activity and glutathione content in type II cells which was not observed in fibroblasts. We conclude that adaptative changes in SOD and glutathione metabolism could be important defence mechanisms in cells exposed to hyperoxia.

Animals↗
PubMed1991

[Disseminated toxoplasmosis in a patient with HIV infection].

The authors describe a case of toxoplasmosis occurring in a subject who is HIV positive who presented with a cough and an infectious syndrome. Toxoplasma gondii was identified in the broncho-alveolar lavage even though the X-ray, the fibroscopy, blood gases and the broncho-alveolar lavage were normal. The frequency of pulmonary disease in the course of a toxoplasma infection in HIV subjects was underlined. Amongst the non invasive diagnostic methods the authors stress the value of broncho-alveolar lavage with a close search for toxoplasma even in the absence of any suggestive paraclinical anomalies.

Adult↗
PubMed1991

[Filarial eosinophilic lung. Apropos of a case].

Pulmonary eosinophilia due to filariasis is a form of filarial infection which is frequent in endemic zones but very much rarer in Europe where it is always "imported". In this case report the authors specify the clinical characteristics and pathophysiology of this disease.

Adolescent↗
PubMed1990

The respiratory response to CO2 and O2 in patients with coma due to voluntary intoxication with barbiturates and carbamates.

We have investigated the respiratory response to CO2 and to O2 in comatose subjects self intoxicated with barbiturates and carbamates. The chemical drive of 12 such patients with coma was compared with that of comparable normal subjects. The ventilatory response to CO2 was depressed but the P0.1 response was of the same order of magnitude as in normals. O2 had little effect on the ventilatory parameters and occlusion pressure. There was no difference between the two groups of patients, indicating that the respiratory changes observed were more dependent on the intensity of the intoxication than on the nature of the drugs. In addition, mechanical factors seem mainly responsible for the depressed ventilatory response to CO2.

Adult↗
PubMed1990

The transition between apnoea and spontaneous ventilation in patients with coma due to voluntary intoxication with barbiturates and carbamates.

We have investigated the transition from apnoea to spontaneous breathing in five comatose patients self intoxicated with barbiturates and carbamates. All patients were apnoeic on admission, and were studied throughout the course of recovery. The transition between the first respiratory movements and a stable and nearly normal ventilation (stable respiratory activity) ranged from 15 to 105 min, a very short time compared to the duration of the apnoeic state that lasted 6 to 72 h from admission. Minute ventilation and occlusion pressure during the first respiratory movements were 6.3 +/- 2.7 l.min-1 and 1.35 +/- 0.45 kPa, respectively. These values increased by roughly 50 and 100% by the time stable respiratory activity was achieved. The increase in minute ventilation was entirely due to an increased inspiratory flow, in relation to a proportionate increase in occlusion pressure, and without significant changes in the respiratory times or in the effective elastance. We conclude that the transition between apnoea and stable respiratory activity is characterized by its rapidity, by the fact that respiratory times are fixed throughout the recovery process, and by the fact that effective elastance is high.

Adult↗
PubMed1988

[Decision analysis: application of a diagnostic and therapeutic strategy in cases of bronchial carcinoma].

Faced with a constant development of new methods of treatment and diagnosis, the clinician does not always have an easy task: the multiplicity of options available makes it difficult to take decisions guaranteeing both maximum safety of diagnosis with a reasonable number of examinations. In relation to this problem the respective places of CT scanning, mediastinoscopy and exploratory thoracotomy in the search for metastatic mediastinal adenopathy in the course of the local and regional assessment of a bronchial carcinoma are considered. In this situation the general principles of decision analysis can be contemplated: the characteristics of the test (sensibility and specificity), the prevalence of the disease and Bayes theorem and the concept of utility. The consequences flowing from this approach are analysed.

Carcinoma, Bronchogenic↗
PubMed1987

A controlled study of oxygen metabolite release by alveolar macrophages from children with interstitial lung disease.

The ability of alveolar macrophages (AM) to release O2 metabolites was studied in 8 children with interstitial lung disease (ILD), and in 11 children without lung parenchyma disorder. AM were collected by bronchoalveolar lavage. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate (PMA) or zymosan. Our results indicated that, with or without triggering agent, the amount of O2 metabolites release was a linear function pattern with time. The accumulation of superoxide anion (O2-) and hydrogen peroxide (H2O2) into the extracellular medium differed depending on the triggering agent used: with PMA, the amount of O2- released was threefold the amount of H2O2 detected in the medium, whereas with zymosan the O2- accumulation was tenfold higher than the amount of H2O2 measured. In patients with ILD, a significant increase in the amount of H2O2 release was observed for both unstimulated and stimulated AM (p less than 0.001). In this group, the measurement was repeated after a 2-month steroid treatment: prednisone had markedly improved the clinical, radiologic, and functional status of the patients, and this improvement was in good correlation with the decrease of O2 metabolite production. The amount of H2O2 release in each case was within the range of control values. Evaluation of O2 metabolite release by AM could be a useful parameter in the assessment of the activity of ILD.

Adolescent↗