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Biomedical subjects

J L Clement

Publications and source records attributed to J L Clement.

29 records · Page 2Linked to original sources
PubMed1981

Epidural morphine causes delayed and prolonged ventilatory depression.

We measured ventilation, PETCO2 and the Ventilatory response to added carbon dioxide before and at intervals up to six hours after epidural morphine 3.5 mg and 7.0 mg, and before and after subcutaneous injections of the same dose in volunteers. Subcutaneous morphine increased PETCO2 slightly, but did not alter the sensitivity of the response to added carbon dioxide. Epidural morphine reduced ventilation and increased PETCO2 progressively with time and, six hours after injection, reduced the ventilatory response to carbon dioxide considerably. In two subjects tested, these ventilatory effects persisted for twenty-four hours. The added effects of epidural morphine were due primarily to reductions in tidal volume and the tidal volume response to added carbon dioxide. We conclude that epidural morphine causes delayed and very prolonged ventilatory depression, which is of a greater magnitude and a different ventilatory pattern than that which follows the same does of morphine given subcutaneously. Ventilatory depression after lumbar epidural morphine develops slowly, as the lower limb analgesic effect is waning.

Adult↗
PubMed1981

Ultrastructural study of the medulla of mammalian hairs.

Coordinated studies with the SEM and CTEM have allowed the authors to observe in situ the morphology and ultrastructure of about twenty different types of hair selected on the basis of their different characteristics when studied by optical microscopy. The new data thus obtained make it possible to classify the different types of hairs in a logical order (parallel to Hausman's classification). The classification is based on the fine morphology and the ultrastructure of the medulla and the differences encountered in the main mammalian orders. Furthermore the chronology of these characteristics follows that of mammalian phylogenesis. The ultrastructural characteristics of the medullar of human hair are totally different from those of the hair of all other mammals.

Animals↗
PubMed1980

Surgical stimulation does not enhance ventilatory chemoreflexes during enflurane anaesthesia in man.

To assess the impact of surgical stimulation on regulation of ventilation in anaesthetized man, we measured ventilation and the ventilatory responses to either hyperoxic hypercapnia or to isocapnic hypoxaemia in fifteen subjects anaesthetized with enflurane 1.1 MAC, just prior to and then during a surgical procedure. Anaesthesia alone reduced ventilation, increased PaCO2, decreased the response to carbon dioxide and virtually abolished the response to hypoxaemia. The addition of operation at the same level of anaesthesia augmented ventilation and reduced PaCO2, but did not improve the anaesthesia-induced impairment of the responses to hypercarbia and hypoxaemia. Over the range of PCO2 and PO2 values studied, the effects of surgery were constant and independent of chemical drive.

Adult↗
PubMed1979

Ventilation and chemoreflexes during enflurane sedation and anaesthesia in man.

Enflurane sedation and anaesthesia in healthy fit subjects reduced ventilation and the response to carbon dioxide, hypoxaemia and a low dose of doxapram, all in a dose-related fashion. Comparing the three chemoreflexes tested, the response to hypoxaemia and doxapram were the more profoundly impaired; they were nearly totally abolished by anaesthesia. These effects of enflurane on chemoreflex activities are qualitatively similar to those previously observed with halothane.

Adolescent↗
PubMedDate not supplied

Chiari pelvic osteotomy in Perthes disease.

A retrospective study of 17 Chiari osteotomies performed on patients with Perthes disease who were followed until the end of growth is presented. The average age at operation was 8 years 9 months. Catterall grading was mainly group IV. Chiari osteotomy provided satisfactory femoral head coverage with a decreased acetabular index and a 19.6 degrees improvement of the Wiberg angle. Good femoral coverage was related to age at operation and the site of the osteotomy on the upper rim of the acetabulum. The postoperative result was less successful on younger patients or when the osteotomy was performed higher. At follow-up, the results of femoral head sphericity studied by Mose measurements were favorable under Catterall grading.

Acetabulum↗
PubMedDate not supplied

Exaggerated femoral anteversion and acetabular development: experimental study in growing dogs.

Femoral excessive anteversion caused by femoral osteotomy in growing dogs is an accurate dynamic model of experimental acetabular dysplasia. Radiographic and CT scan examinations were performed throughout the growing period. Evolution showed an incomplete femoral detorsion. It induced acetabular developmental modification leading to an anterior and superior acetabular dysplasia. At the end of the growing period, hips were not dislocated, but signs of femoral and acetabular osteoarthritis were obvious, which shows the importance of mechanical force modification in the creation of experimental osteoarthritis. The links between hip osteoarthritis and exaggerated femoral anteversion are discussed. Might acetabular dysplasia be secondary to femoral anteversion, which could justify a corrective osteotomy during childhood? Our experiment leads to a better comprehension of this phenomenon.

Acetabulum↗