PubMed Health⌕ Search

Biomedical subjects

B Cathala

Publications and source records attributed to B Cathala.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Aggregation during coniferyl alcohol polymerization in pectin solution: a biomimetic approach of the first steps of lignification.

Coniferyl alcohol was polymerized in pectin solution in order to mimic the lignification that is the final step of biosynthesis of plant cell wall. Dehydrogenated polymers (DHP = coniferyl alcohol polymers = synthetic lignin) interact with pectin to form hydrophobic clusters as monitored by pyrene fluorescence spectroscopy. The structure of these clusters was studied during the polymerization of synthetic lignin by static and quasielastic light scattering and small angle neutron scattering experiments. We show that synthetic lignin and pectin contribute to the same clusters, but the inner structure of these clusters is very heterogeneous and displays three phases. One observes a segregation between well separated pectin and lignin rich phases at length scales below approximately 30 nm. As a corollary of this segregation, clusters embody a large amount of solvent. On average, the density of the polymer rich phase (lignin plus pectin) inside clusters increases while its specific surface area decreases throughout the polymerization process. These results are discussed with respect to in vivo lignification of the plant cell wall.

Biomimetic Materials↗
PubMedDate not supplied

[Propofol in emergency anesthesia].

Thirty-two patients (14 women and 18 men) whose age ranged between 15 and 76 were admitted on an emergency and anesthetized with propofol in view of various surgical interventions (9 appendectomies, 9 fractures, 5 wound healing, 6 abscess incisions, 2 corneal grafts and one complex trauma surgery) undergone 24 hours after their admission. Premedication included hydroxyzine 1.5 mg.kg-1, atropine sulfate 0.5 to 0.75 mg and pethidine 1 mg.kg-1 according to pain intensity and initial pathology. Narcosis was induced by 2.5 mg.kg-1 propofol injected intravenously. Propofol was then administered continuously at a dose of 9 mg.kg-1 in the first hour and of 4.5 mg.kg-1.h-1 in the following hours for 28 of the patients. Four patients undergoing short operations were given additional injections of one third of the initial dose. Analgesia and myorelaxation were obtained with fentanyl (0.16 +/- 0.06 mg) and vecuronium (9.3 +/- 4 mg). Narcosis proved to be very efficient. The side effects observed (13% myoclonia, 6% rash, 6% bradycardia, 0.3% pains at the time of injection) were similar to those quoted in the literature. Blood pressure stabilized after a short slight depression (13% to 18% of the standard values). Pulse remained regular. We can thus say that propofol is a good hypnotic drug for emergency anesthesia provided that its contra-indications especially shocks of cardiac or septic origin and hypovolemia, are carefully respected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Study of home ventilation in severe respiratory insufficient patients (author's transl)].

Results of our study of 91 cases show that many indications of ventilation at home are debatable:--Tracheostomized patients submitted to continuous ventilation with short disconnected periods;--Patients using the respiratory apparatus more than 4--6 hours per day, through a mouth-piece. The existence of a reserve closely related to the intensive care department and mobile emergency unit (S.A.M.U.) facilitates supervision and eventual technical or medical assistance. In addition, the running cost remains small because of the adaptability of the system. However, it seems of interest to point out a group of 11 patients whose treatment was interrupted either because of their improvement (physical therapy, suppression of tobacco mainly), inadequate indications, or poor cooperation.

Aged↗