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Biomedical subjects

P Scheinmann

Publications and source records attributed to P Scheinmann.

At least 163 records · Page 9Linked to original sources
PubMed1985

Inverse correlation between tumor incidence and tissue histamine levels in W/WV, WV/+, and +/+ mice.

The influence of mast cells on tumor incidence and growth rate was studied in 2 grafted tumor models (fibrosarcoma MC-B6-1 and the Lewis lung carcinoma 3LL). Three kinds of WBB6F1 mice (a cross between WB/ReJ-W/+ and C57BL/6J-WV/+ mice) were used: W/WV (deeply mast cell depleted), WV/+ (partially mast cell depleted), and +/+ (normal mast cell number). The presumed resistance of F1 hybrids to tumor cells of parental origin was observed in 12 of 13 +/+ mice, but only in 11 of 22 WV/+ mice and in none of 39 W/WV mice. Tumor incidence and metastasis incidence were inversely correlated with tissue histamine levels and mast cell number. Growth rates of tumors were similar in W/WV and WV/+ mice, but the tumor growth rate was much slower in the only +/+ mouse in which the tumor grew. These results confirm the protective role of mast cells against tumors.

Animals↗
PubMed1984

[Glucocorticoids in pneumology].

Their antiinflammatory effect is the chief reason why glucocorticoids are used in pneumology. By diminishing capillary permeability, glucocorticoids slow passage of fluids and cells towards locations of inflammation. As they promote recirculation of polymorphonuclear neutrophils and conversely decrease eosinophil, basophil, lymphocyte and monocyte blood counts, cellular reaction is curtailed. Lastly, glucocorticoids antagonize release of enzymes and mediators by inflammatory cells and have an immunosuppressive action which predominates on T cells. In asthma, in addition to their anti-edema effect, they potentiate or restore the action of bronchodilators. Parenteral administration of glucocorticoids is mainly indicated in emergency settings; oral glucocorticoids are used in maintenance therapy which relies chiefly on short half-life derivatives (prednisone, prednisolone, methylprednisolone) whose suppressive effect on the hypothalamo-pituitary axis is less than that of intermediary or long half-life corticosteroids. Lastly, aerosol forms have a chiefly preventive action and require that the respiratory tract be clear to be efficient. Main indications of glucocorticoids are those conditions in which immunologic and/or inflammatory reactions have a deleterious effect: in asthma, combined with bronchodilators, glucocorticoids are the mainspring of management of severe attacks and protracted, severe asthma; corticosteroid aerosols have the advantage that systemic corticosteroid therapy can be avoided or shortened, thereby lessening the risk/benefit ratio; extrinsic allergic alveolitis, sarcoidosis with multiple localizations, and/or respiratory impairment, and protracted pulmonary eosinophilia, are choice indications for systemic corticosteroid therapy; glucocorticoids may be insufficiently effective in idiopathic pulmonary fibrosis or respiratory localizations of vasculitis, which may justify association of immunosuppressants; indications of glucocorticoids in certain forms of tuberculosis or cancer of the respiratory tract are less clearly systematized.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Tissue histamine levels and mast cell numbers in tumour-bearing mice.

In C57BL/6 mice bearing the 3LL carcinoma and in C3H mice bearing the McC3 -1 fibrosarcoma (18th passage), the increase in skin histamine levels was correlated with the increase in mast cell number. The number of cells able to incorporate tritiated thymidine was proportional to the mast cell number. These results strengthen the notion that, in tumour-bearing rodents, the increase in tissue histamine is an active phenomenon.

Animals↗
PubMed1984

A study on the reproducibility of specific bronchial provocation testing in children.

Bronchial provocation tests with housedust were carried out on thirty-five asthmatic children aged 4-13. Each patient was tested twice. Subjects were studied with two different doses of allergen: 1200 and 3600 micrograms. There was reproducibility in 80% of the seventy tests performed, allowing confirmation of the reliability of the test. Furthermore, reproducibility was better when lower doses of allergen were inhaled. The intensity of the bronchial response sometimes varied in the same subject. These variations were greater when the inhaled volume increased. Immediate and delayed reactions together and delayed reactions alone were frequent (60% of cases); this should therefore be taken into account when studying the reproducibility of specific bronchial provocation test.

Adolescent↗
PubMed1984

Pulmonary infiltrate with eosinophilia in a 14-year-old child.

A prolonged case of pulmonary infiltrates with eosinophilia of the lung was submitted to a large immunological enquiry. The biological results, added to the immunofluorescence study of a lung biopsy, militated for a complex underlying immune mechanism with, on one hand IgE, eosinophils and mast cells, and on the other hand plasma cells and IgG.

Adolescent↗
PubMed1983

[Viruses and asthma].

More than one-third of infants with respiratory syncytial virus (RSV) bronchiolitis subsequently experience recurrent episodes of wheezing. In asthmatic children, viral infections frequently trigger asthmatic attacks. Indeed, viruses induce immunological and respiratory functional disorders. As compared with non-wheezing RSV infected infants, wheezing infants with bronchiolitis or asthma due to RSV have: a) increased T-lymphocyte responsiveness to RSV antigen; b) more persistent IgE bound to nasopharyngeal epithelial cells; c) higher titers of RSV-specific IgE and higher histamine concentrations in nasopharyngeal secretions. In children with an atopic constitution, virus infections may trigger allergic sensitization. Furthermore, some viruses enhance the immunologic and non-immunologic human basophil histamine release. Non-specific bronchial hyperreactivity, which is a fundamental feature of asthma, can also be observed to a variable degree in viral respiratory infections. Pulmonary function testing allows in vivo determination of bronchial sensitivity and bronchial reactivity (respectively threshold dose and dose-response curves). Four factors may be involved in bronchoconstriction: a pre-existing diminution of bronchial diameter (which is lacking in many studies); hyperplasia or hypertrophy of bronchial muscles (which is to be excluded in recent viral infections); a non-specific decrease in the threshold for stimulation of irritant receptors due to airway epithelial injury; a partial beta blockade. Further studies are needed to ascertain whether this bronchial hyperreactivity is congenital or acquired.

Animals↗
PubMed1983

[Bronchiolitis obliterans: technics of exploration and diagnosis].

Bronchiolitis obliterans is an anatomo-clinical entity which may, in young pediatric patients, follow severe viral infections, especially due to measles virus and adenoviruses. After a transient remission, the disease progresses to chronic respiratory failure with dyspneic paroxysms. Diagnosis is based on different investigations which confirm the absence of proximal bronchiolar obstruction and the presence of bronchiolar obliteration. Deficient pulmonary perfusion due to ventilatory defects are demonstrated by pulmonary scintigraphy and even better by digital subtraction pulmonary angiography. Obliteration of non-cartilaginous bronchioli by granulation tissue produces bronchiolar destruction and explains the permenence of alterations. Dissimilarity of the responses of children to acute respiratory viral infection remains unexplained. The degree of the viral load and of the initial immune deficiency as well as the persistence of the virus within the pulmonary tissue probably account for the chronic pulmonary damage.

Adenovirus Infections, Human↗
PubMed1983

Selective increased tissue histamine levels in tumour-bearing rodents.

Histamine levels increased in the fundus of mice bearing a primary 3-methylcholanthrene-induced fibrosarcoma, and in the ventral skin, skeletal muscle and rumen of rats bearing a D.M.B.A. induced mammary adenocarcinoma; they did not increase in the tissues of mice bearing a McC3-1 fibrosarcoma (38th passage) or a Lewis lung carcinoma before the appearance of metastasis, but an increase in histamine levels was observed in dorsal skin, ventral skin and fundus, after the appearance of metastasis.

Animals↗
PubMed1983

Decreased blood histamine levels in patients with solid malignant tumours.

In a one-year follow-up study, 444 blood histamine determinations were performed in 163 patients with solid malignant tumours. Compared with normal subjects, blood histamine levels were significantly lower in patients with unresected primary tumours (30.7 +/- 19.9 ng ml-1), metastases (34.1 +/- 17.1 ng ml-1), or both (24.5 +/- 12.8 ng ml-1). By contrast, after successful tumour resection, histamine blood levels were nearly normal (52.1 +/- 18.4 ng ml-1, versus 59.6 +/- 22.6 in control patients). Stability of the histamine blood levels was associated with stability of the disease. A progressive decrease in histamine blood levels preceded clinical relapse or detection of metastasis. In patients with consecutive histamine blood levels which were less than 15 ng ml-1, survival did not exceed 2 months. In patients with gastrointestinal tumours, blood histamine levels provided information additional to that derived from serum CEA determination. In patients with non-gastrointestinal tumours, the blood histamine level may be of more value than CEA as a marker of disease progression.

Adult↗