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Biomedical subjects

F Gauthier

Publications and source records attributed to F Gauthier.

At least 199 records · Page 11Linked to original sources
PubMed1982

Kinetics of the inhibition of leukocyte elastase by the bronchial inhibitor.

The rate constant for the association between human leukocyte elastase (EC 3.4.21.11) and human bronchial inhibitor has been determined by competition experiments with alpha 1-proteinase inhibitor. This constant (1.1.10(7) M(-1) . s(-1)) is 6-times lower than that for the association of leukocyte elastase and alpha 1-proteinase inhibitor. The latter inhibitor is able to dissociate the leukocyte elastase-bronchial inhibitor complex with a rate constant 1.3.10(-4) s-1. The equilibrium dissociation constant Ki of the complex is 1.2.10(-11) M. The physiopathological significance of these constants is discussed.

Bronchi↗
PubMed1982

[Phimosis].

Explore the source record for details and available documents.

Circumcision, Male↗
PubMed1981

The interaction between rat plasma alpha 1 inhibitor 3 and chymotrypsin. A protease-protease inhibitor system which gives partially active complexes.

Complexation of chymotrypsin with rat alpha 1 inhibitor 3 (alpha 1I3) leads to a significant modification of circular dichroism (CD) spectra in the near ultraviolet. These spectra variations are due to structural changes of the inhibitor resulting from partial proteolysis. Taking advantage of this change in CD spectral properties a 1:1 stoichiometric ratio was determined for the interaction. However, when an excess of inhibitor was present in the mixture, a slow change of the CD spectrum was observed. This was shown to result from a partial proteolysis of native inhibitor identical to that occurring during complex formation. This hydrolysis was due to the remaining activity of the bound enzyme since no significant release of free enzyme from the complex was demonstrated. Addition of human alpha 1 proteinase inhibitor (alpha 1 Pi) to dissociate the complex resulted in the formation of an enzymatically inactive ternary complex which gave evidence for the stability of the alpha 1I3 chymotrypsin binding.

Acute-Phase Proteins↗
PubMed1981

Identification and possible regulation of muscle cell lysosomal protease activity by exogenous protease inhibitors.

Using immunohistochemical or histochemical techniques lysosomal proteases have been localized in muscle cells. These include two exopeptidases (dipeptidyl peptidase I and II) and three endopeptidases (cathepsins B, D, and H). In general, the enzymes varied in apparent activities with the soleus muscle always more reactive than the extensor digitorum longus (EDL) of the rat. Cathepsin B and dipeptidyl peptidase I were localized primarily in subsarcolemmal regions whereas cathepsin H and dipeptidyl peptidase II were scattered throughout the sarcoplasm consistent with other observation of two populations of muscle lysosomes. However, cathepsin D could not be localized in either type of lysosome by similar histochemical techniques. Using immunohistochemical techniques, the protease inhibitors alpha 1-antitrypsin and alpha 1-inhibitor3 were recognized in intracellular compartments within muscle cells. alpha 1-antitrypsin appeared scattered throughout the cytoplasm while alpha 1-inhibitor3 was localized in discrete subsarcolemmal regions. Both inhibitor content and protease activity were diminished in skeletal muscles following streptozotocin-induced diabetes.

Acute-Phase Proteins↗
PubMed1980

Purification and physicochemical characterization of a new rat plasma proteinase inhibitor, alpha 1-inhibitor III.

A three-stage procedure was used to isolate an additional proteinase inhibitor in rat plasma tentatively called alpha 1-inhibitor III. A 20% yield was obtained after two successive gel filtrations on Ultrogel Ac-A. 33-4 followed by an ion-exchange chromatography on DEAE-cellulose. This method was chosen since it permits further study of the enzyme binding properties of the isolated molecule. The purified material was first controlled to retain an inhibiting capacity towards serine proteinases using bovine chymotrypsin. The isolated molecule has an apparent molecular weight of 215 000, a pI of 4.65, an E1%1cm, 280 nm of 7.50 and a sedimentation coefficient of 8.6 S. It contains approx. 15% carbohydrates and is made up of a single peptidic chain. Study of the periodic structure by circular dichroism has demonstrated a low alpha-helix content (4--5%) whereas the beta-sheet conformation accounts for approx. 30% of the peptidic moiety. Tryptophan residues have been shown to be mainly responsible for the molecular fluorescence most of them being non-accessible to the solvent since only 25% of the tryptophanyl fluorescence was quenched in presence of I.

Acute-Phase Proteins↗
PubMed1980

[Esophageal atresia and gastro-esophageal reflux].

Gastro-esophageal reflux has been noted in 60% out of 113 cases of esophageal atresia treated successfully at the Hôpital Saint-Vincent-de-Paul, between the years 1970 and 1978. The tolerance of the reflux in these 58 cases has been variable : 13 children developed severe respiratory complications; 17 children had a stricture at the anastomosis site. Although the general outcome for this type of reflux should be favorable, either spontaneously or by medical means, surgical treatment, usually by fundoplication occasionally may be indicated; 15 children were operated. One died from reflux complications before the operation could be planned. It is possible that the severity of the reflux may be related to the extensive dissection and the tension needed to achieve approximation of the two esophageal segments during repair of the atresia. Some aggravation factors leading to respiratory complications, such as tracheomalacia, and tracheal compression by innominate artery would be an indication for an early anti-reflux operation.

Child, Preschool↗
PubMed1979

Interactions in vitro and in vivo between rat serum protease inhibitors and anodal and cathodal rat trypsin and chymotrypsin.

Reaction mixtures of increasing amounts of the pancreatic homologous proteases, anodal and cathodal chymotrypsin and trypsin, respectively, and normal rat serum were analyzed by immunoelectrophoretic methods in order to determine their distribution on serum protease inhibitors. This paper concerns three proteins occurring in normal serum and capable of binding protease viz. alpha1-macroglobulin, alpha1-antitrypsin and alpha1-inhibitor 3. The distribution of the enzymes among these protease inhibitors differed significantly from one protease to another. The distribution of the proteases among the serum protease inhibitors following intravenous injection of 125I-labelled proteases corresponded to that in vitro. Complexes formed with alpha1-macroglobulin and alpha1-inhibitor 3 were quickly eliminated irrespective of the enzyme species used, whereas those formed with alpha1-antitrypsin persisted much longer in the circulation.

Animals↗
PubMed1979

[Congenital anorectal stenosis (8 cases) (author's transl)].

The authors present a series of 8 cases of congenital anorectal stenosis treated recently, with a follow up of 1 to 7 years. The finding of 3 poor results from the standpoint of anal continence leads to a discussion of the general prognosis of this malformation classically considered as being benign.

Anal Canal↗
PubMed1979

[Ovarian cysts and tumors in neonates, infants and children (author's transl)].

Twenty-six girls, aged from 0 to 15 years, were operated, upon ovarian cysts and tumors from 1952 to 1977. Before the age of one year, 11 non-neoplastic cysts and 2 benign tumors were observed. After the age of one, 1 non-neoplastic cyst and 12 tumors: 8 germ-cell tumors, 3 tumors of specialized gonadal stroma, and one epithelial tumor. Three germ-cell tumors were malignant (1 girl dead of disease, 2 alive at 2 and 1 1/2 years). All three gonadal stromal tumors are benign (with a follow-up of 3 months, 4 and 20 years). Epidemiology, pathology prognosis and management of these tumors are discussed according the recent literature.

Adolescent↗
PubMed1978

The in vitro interactions of rat pancreatic elastase and normal and inflammatory ray serum.

The partition of labelled rat pancreatic elastase (EC 3.4.21.11) between the different protease inhibitors of rat plasma was studied at different levels of saturation of the inhibitors of rat plasma was studied at different levels of saturation of the inhibitor capacity of plasma with the enzyme. The reaction mixtures were analysed by immunoelectrophoretic methods utilizing specific antisera against the different inhibitors and by gel filtration on Sephadex G-200. Rat serum was shown to contain four elastase binding proteins. alpha 1-antitrypsin, alpha 1-macroglobulin and alpha 2-acute phase protein and alpha 1-inhibitor 3 which exhibits immunologic cross-reaction with human inter-alpha-trypsin inhibitor and is of similar molecular weight. With minute amounts of labelled elastase the partition among the binding protein was alpha 1-macroglobulin 60%, alpha 1-antitrypsin 24% and alpha 1-I3 16%. The 60% value of alpha 1-M bound radioactivity in normal serum corresponds to the sum of alpha 1-M and alpha 2-AP labelling in inflammatory serum.

Acute-Phase Proteins↗
PubMed1978

Isolation and some properties of a new enzyme-binding protein in rat plasma.

alpha-1-Inhibitor3 (alpha-I3), a new enzyme-binding protein, was isolated from rat plasma by a combination of ammonium sulfate precipitation, ion exchange chromatography on DEAE cellulose and gel filtration on ultrogel AcA34. Agarose gel electrophoresis of the purified inhibitor showed a single protein band with alpha1-mobility giving a single precipitation line on immunoelectrophoresis against anti-rat serum. A specific antiserum against the purified inhibitor was raised in rabbits. alpha1-I3 showed immunologic cross-reaction with human inter-alpha-trypsin inhibitor. alpha1-I3 formed a complex with trypsin, which was thereby inhibited; the electrophoretic mobility of the complex was less than that of free inhibitor. Inflammation, induced by turpentine, caused a decrease in the serum concentration of alpha1-I3 to 36% of the initial value within 48 h. alpha2 acute phase macroglobulin (alpha2-AP) showed a simultaneous increase to 7.1 g/l and alpha1-antitrypsin (alpha1-AT) to twice its normal value.

Alpha-Globulins↗
PubMed1976

Rat alpha2 acute-phase macroglobulin. Isolation and physicochemical properties.

1. Rat alpha2 acute-phase macroglobulin was isolated from turpentine-injected rats by Sephadex G-200 chromatography and ion-exchange chromatography on DEAE-cellulose. This method, since it does not include (NH4)2SO4 treatment, allows the study of the physicochemical as well as the biological properties of the molecule. 2. The purity of the preparation was demonstrated by ultracentrifugation, polyacrylamide-gel electrophoresis, fused "rocket" immunoelectrophoresis as well as double immunodiffusion. 3. The rat alpha2 acute-phase macroglobulin was characterized in terms of its main physical and chemical properties. Its isoelctric point was determined by isoelectrofocusing to be 4.55; s020,w was 18.4S and E1%/1cm at 278 nm was 6.8. The mol.wt. was determined by light-scattering to be 770000. 4. The amino acid content was compared with that of rat alpha1 macroglobulin and was found very similar. The carbohydrate composition of alpha2 acute-phase macroglobulin was determined to be: hexose, 4.25%; glucosamine, 3.4%; sialic acid, 2%; fucose, 0.2%. From these results it was concluded that alpha2 acute-phase macroglobulin, although a typical acute-phase reactant, possesses the characteristic physicochemical properties of alpha macroglobulins.

Amino Acids↗