Search PubMed⌕ Search

Biomedical subjects

A Michel

Publications and source records attributed to A Michel.

At least 217 records · Page 12Linked to original sources
PubMed1981

Operations on the colon without preoperative oral antibiotic therapy.

The ideal preparation of the intestine prior to elective colonic resection has been a controversial subject. With the development of new and more effective antibiotics, many modalities of intestinal preparation preoperatively have been used in an effort to reduce the number of infectious complications. Mechanical cleansing of the intestine, when accompanied by perioperative parenteral antibiotics, is adequate preparation prior to resection of the intestine. One hundred consecutive operations upon the colon by one surgeon were the subject of this retrospective study. Approximately 70 per cent of the operations were for carcinoma and the remainder for inflammatory disease. Preparation consisted of the administration of cathartics and saline solution enemas combined with a liquid diet for 48 hours prior to operation. Perioperative parenteral antibiotic therapy was given for 48 to 72 hours or as long as intravenous fluids were administered. All anastomoses were the open, two layer type, using nonabsorbable suture material. All abdominal incisions were closed primarily. There were no operative deaths, anastomotic leaks, intra-abdominal abscesses or fistulas. There were six instances of wound infection. Our results with this type of management compare favorably with those of other surgeons using various modes of preoperative oral antibiotic therapy and suggest that oral preoperative antibiotic therapy may not be necessary in elective operations on the colon.

Administration, Oral↗
PubMed1979

The conformational properties of some fragments of the peptide hormone somatostatin.

The conformational properties of some somatostatin fragments have been studied using high resolution NMR and semi-empirical calculations. The fragments are Thr10-Phe11, Phe11-Thr12, Thr10-Phe11-Thr12 and Thr10-Phe11-Thr12-Ser13. The results of high resolution 1H and 13C NMR using dimethylsulfoxide and 2H2O as solvents, combined with a new method for determining dihedral angles phi and psi from 13C and 1H spin lattice relaxation times are presented. A marked inequivalence of the two Thr10,12 residues is attributed to a shielding of the the Thr10 side chain by the Phe11 aromatic ring. The calculations show the existence of extended and folded low energy conformations in the tri and tetrapeptide. Only the folded structures give the observed shielding of Thr10. A temperature study of the tri and the tetrapeptide indicates that the folded structures are energetically the most favorable conformations at room temperature in dimethylsulfoxide. Increasing temperature reduces the nonequivalence of the Thr residues towards the differences that are observed in 2H2O. A detailed comparison of 3JalphaNH coupling constants and relaxation time measurements with the calculated conformations gives in general good agreement between both approaches. It is concluded that in these linear peptides, although several quite different low energy conformations exist, some of them are predominant. The continuity of both NMR parameters and calculated low energy conformations, when going from the smaller to the larger peptides, demonstrates the existence of structural properties far from the "random conformation".

Dimethyl Sulfoxide↗
PubMed1979

[Erythropoietin and erythropoiesis inhibition factor in the newborn and infants with cyanotic heart abnormalities].

In the present study, hematocrit, pO2 in the capillary blood, reticulocyte count, erythropoietin activity in plasma and activity of the erythropoiesis inhibition factor in 24-h collective urine were determined in newborns and infants with cyanotic malformations of the heart (transpositions of the big arteries). The plasma of the healthy newborns shows immediately after birth an erythropoietin activity below 1%, as measured by the 59Fe incorporation. The erythropoietin activity of the plasma of infants with cyanotic malformations of the heart is enhanced up to the 14th day of life. In the period of day 14--30 it corresponds to the values of healthy newborns despite the persistence of hypoxia. After the 30th day of life there is again demonstrable an increased erythropoietin activity in the plasma of infants with cyanotic malformations of the heart. Obviously, the low values of 59Fe incorporation from day 14--30 are due to the occurrence of the erythropoiesis inhibition factor. In the urine of infants with cyanotic malformations of the heart there could be demonstrated distinct inhibitions of the stimulated erythropoiesis of the polycythemic mouse. The present studies suggest that the erythropoiesis inhibition factor occurs in postnatal development irrespectively of the degrees of O2-supply of the tissue, and is possibly dependent on the gestational age.

Aging↗
PubMed1977

Occurrence of tryptophan in the enzymically active site of diphtheria toxin fragment A.

Tryptophan residues of diphtheria toxin fragment A have been modified by 2-hydroxy-5-nitrobenzyl bromide. Fragment A loses its ability to inactivate ADP-ribosylation of the elongation factor 2, as a function of the number of residues modified. Modification of one tryptophan residue provides a dramatic loss of enzymic activity suggesting the presence of one essential residue of this type in fragment A. Examination of fingerprint maps of chymotryptic peptides of fragment A after reaction with 2-hydroxy-5-nitrobenzyl bromide allows us to identify this tryptophan residue at position 153 of the amino acid sequence. ORD and CD experiments joined to immunochemical studies seem to exclude the possibility that the observed decrease in the enzymic activity may be attributed to a conformational change. Finally, results of nicotinamide-adenine dinucleotide-binding measurements suggest that tryptophan 153 would be concerned with the elongation factor 2 binding site or with the catalytic site itself.

Benzyl Compounds↗
PubMed1977

[The pre- and postoperative 2,3-diphosphoglycerate concentration of erythrocytes in children with cyanotic heart disease].

The behaviour of 2,3-diphosphoglycerate concentration (2,3-DPG) of red blood cells of babies and children with cyanotic heart diseases is studied before and after shunt operations. In babies with cyanotic heart diseases at the age of up to 6 months an increase of 2,3-DPG-level and haematocrit (HCT) is seen. Later, the compensation of chronic hypoxia is effected by further increase of HCT at unchanged high 2,3-DPG-level. The 2,3-DPG concentration which is still increased after successfull shunt operations as compared with the normal value is considered as an effective adaptation mechanism to the residual hypoxia presenting only a small load on the circulatory system. The 2,3-DPG concentration alone does not represent a criterion for the assessment of chronic hypoxia.

Adolescent↗
PubMed1976

[Surgery of cancer of the larynx. The patient in the pre-, per-, and postoperative period].

Surgery of tumours of the larynx requires two main types of operation: -Extensive laryngeal surgery including: -the full pre-operative assessment and preparation of the patient's general condition which is always poor, e.g. due to alcoholism or respiratory failure. -variable techniques, adapted to the lesion, for the control of the patency of the upper airway. -operative risks, such as: reventilation shock, reflex cardiac arrest, disorders of cardiac rythm and gas embolism. -Its complications: -may be immediate and poorly specific, especially respiratory, neurological and infective. -secondary and more specific e.g. Pharyngostoma, and tracheal stenosis. -late complications due to spread of a malignant process. -Laryngeal surgery limited to one vocal cord for which local anaesthetic, improved by neuroleptanalgesia, such as Diethazine-Diparcol, best meets the surgeon and the interest of the patient.

Alfaxalone Alfadolone Mixture↗