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Biomedical subjects

C Dupont

Publications and source records attributed to C Dupont.

At least 271 records · Page 15Linked to original sources

[The value of respiratory function tests in the surveillance of asthmatic children].

The purpose of pulmonary function testing in children with asthma is to search for obstructive airway disease. We examined the charts of 169 asthmatic children during intervals between acute exacerbations. The severity of asthma was determined according to VIALATTE classification, with the Tiffeneau ration FEV1/VC (1) and the MMFR/VC ratio serving as obstructive indices. According to these data, children were classified into three groups: normal children (normal FEV1/VC and MMFR/VC), children with probable obstruction of the distal airways (normal FEV1/VC and decreased MMFR/VC), and children with both proximal and distal airway obstruction (decreased FEV1/VC and MMFR/VC). Since suggested normal values vary in the literature, we compared FEV1 and MMFR to determine as accurately as possible the number of children with obstructive disease. The relationship between the degree of clinical involvement and pulmonary function testing results was studied. Clinically, asymptomatic children with suspected normal respiratory function had evidence of obstructive disease in two out of three cases, and would benefit from drug therapy.

Adolescent↗

[A radio-endoscopic case: Barrett esophagus in children].

The authors report a case of Barrett's oesophagus in a child. This observation is characterized by the extent of the lesion which is of three types of metaplasic epithelium usually seen in this disease (fundic, cardial and intestinal tissue); the difficulties in differential diagnosis from uncomplicated hiatal hernia justify radiological and endoscopical examinations with multiple biopsies. The discussion centers on the risk of malignant transformation with its therapeutical consequences and the long term follow-up of such patients.

Adolescent↗

Ketotifen in prevention and therapy of food allergy.

Ketotifen, benzocycloheptathiophene, (Zaditen) an orally active, anti-allergic and anti-asthmatic drug in a dose of 1 mg twice daily was given from 2 to 20 months in 20 selected patients with food allergy (FA) or food intolerance (FI). Sixteen children and four adults of which ten had atopic dermatitis (AD), six urticaria or/and angiooedema (two of which with oropharynx pruritus, oedema of the lips and anaphylactic shock), two asthma, and two gastrointestinal disorders. Food allergy was proved by clinical history, exclusion diet positive challenge test, skin prick tests (SPT) total IgE (PRIST) and specific IgE (RAST). Gastrointestinal permeability was measured in 5 out of 20 patients using mannitol and lactulose as probe molecules on three occasions: (1) by ingestion of the markers alone, (2) with concomitant ingestion of the offending food(s), and (3) with previous administration of ketotifen (2 mg) six hours before ingestion of markers and offending food. In all five individuals, food ingestion resulted in a significant rise of lactulose: mannitol urinary ratio and previous administration of ketotifen resulted in a normalization of the mannitol:lactulose urinary ratio. Patients with urticaria and/or angiooedema, gastrointestinal symptoms, asthma, and oropharynx pruritus with oedema of the lips were completely protected. In patients with AD, 70% were greatly improved or improved but 30% remained the same. It is our impression that ketotifen offers a new therapeutic dimension and therapy in FA.

Adolescent↗

Is the Year Book really necessary?

The 1980 Year Book of Dermatology was analyzed in detail. Articles were arbitrarily classified as useful, laboratory, and exotic. "Useful" was defined as mainly clinical in content or with obvious clinical relevance. "Laboratory" implied that the author was unable to understand the article because of the predominant biochemical, immunologic, histochemic, or electron-microscopic content involved. "Exotic" meant the article was about a disease that the author had never seen. Of 346 articles analyzed, 270 were found to be useful, 35 laboratory, and 41 exotic. Only 95 of 270 useful articles were in journals that the author normally reads. The Year Books of 1969, 1970, and 1979 contained 1/4, 1/3, and 2/5 useful articles, respectively. Detailed analysis of the above categories was done by subject. Many important articles were present in the literature but were not quoted in the Year Book. It is concluded that the Year Book varies from year to year in its relevance but is still essential reading. The dermatologist must nevertheless amplify it with the standard specialist and general journal; otherwise, important contributions will be missed.

Dermatology↗

Effects of tabernanthine on calcium and catecholamine stimulated contractions of isolated vascular and cardiac muscle.

The Iboga alkaloid tabernanthine (80 microM) non-competitively antagonized contractions in both the rat aorta and mesenteric artery induced by cumulative additions of noradrenaline and calcium. Tabernanthine (8, 40 and 80 microM) antagonized the K+ depolarization-induced contractions of the aorta. Tabernanthine (80 microM) depressed the phasic component of contractions induced by a single maximal concentration (10 microM) of noradrenaline in Ca++ -free solution. Tabernanthine induced a negative inotropic effect in electrically stimulated myocardial tissue and a negative chronotropic effect in the perfused rat heart. Tabernanthine is a calcium entry blocker which also affects cellular calcium metabolism.

Alkaloids↗

[Neuro-hormonal regulation of the function of the enterocyte].

The intestinal epithelial cell, or enterocyte, performs a dual function: absorption and secretion. Absorption takes place in the villi and secretion in the crypts (and perhaps also in the villi). Both functions are controlled by complex extra- and intracellular systems. The extracellular system is mediated by neuromediators released in the subcellular space. Some mediators, like the vasoactive intestinal peptide (VIP) or the prostaglandins, stimulate secretion while others, like enkephalins, stimulate absorption. All these mediators act on intracellular metabolic processes by activating "second messengers" (e.g. amp or intracellular calcium) which in turn regulate the enterocyte transport system. Diarrheogenic processes are frequently due to disturbances in enterocyte control with abnormal stimulation of the secretory processes. Some pancreatic cancers and sympathicoblastomas release VIP into the blood stream in sufficient amounts to stimulate cAMP production by the enterocytes and, consequently, secretion. The cholera toxin and the E-coli thermolabile toxin can also induce stimulation of intracellular cAMP production. Conversely, the most promising antidiarrhoeal drugs are antisecretory agents, like opiates, which stimulate the enterocyte absorption processes.

Animals↗

Beta-adrenergic regulation of cyclic adenosine 3',5' monophosphate accumulation in human gastric epithelial glands. Inhibitory effect of somatostatin.

The action of catecholamines and somatostatin on cyclic adenosine 3',5' monophosphate (cyclic AMP) formation in human isolated gastric glands is reported. We show that: (1) there is a beta 2 receptor-mediated stimulation of cyclic AMP production in fundus. Catecholamines act with the order of potencies isoproterenol (ED50 = 50 nmol 1(-1) greater than epinephrine (ED50 = 0.1 mumol 1(-1] greater than norepinephrine (ED50 = 5 mumol 1(-1]. Their action is completely reversed by propranolol at doses 10(3) times lower than practolol, while unaffected by phentolamine; (2) isoproterenol and Vasoactive Intestinal Peptide (VIP) have additive effects on cyclic AMP in fundic glands whereas no additivity is observed between histamine and isoproterenol; this, together with the absence of catecholamine effect in antral glands, suggests that the beta 2 receptor is located on parietal cells; (3) somatostatin (1 mumol 1(-1] non-competitively inhibits the stimulation by catecholamines but does not affect VIP and histamine stimulations. These results suggest a physiological stimulatory effect of catecholamines on gastric acid secretion in man, through a beta 2 receptor coupled to the cyclic AMP system, regulated by somatostatin.

Catecholamines↗