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Biomedical subjects

B Palmier

Publications and source records attributed to B Palmier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Percutaneous tracheostomy by forceps dilation: report of 162 cases.

A prospective, observational clinical study evaluated the safety of percutaneous single-step dilatational tracheostomy over a 43-month period. One hundred and sixty-two patients were deemed suitable for the procedure. The mean duration of tracheal intubation prior to tracheostomy was 6 days. The mean duration of the procedure was 9.3 min. Intra-operative complications occurred in 27 patients (16.6%), most of which were minor technical difficulties without morbidity. Postoperative complications, some of which were associated with morbidity, occurred in 16 patients. There were two deaths secondary to premature decannulation, one case of severe bleeding and five pneumothoraces. Long-term complications were assessed in 81 patients; there were four tracheal stenoses requiring surgery or laser therapy and seven patients with granulation tissue at the stoma site which did not require treatment. Forceps dilatational percutaneous tracheostomy appeared to be a convenient bedside procedure. However, complications do occur and further studies should address late sequellae, such as tracheal stenosis.

Adolescent↗
PubMed2000

Inositol hexasulphate, a casein kinase inhibitor, alters enamel formation in cultured embryonic mouse tooth germs.

Post-translational modification of enamel proteins is regulated by casein kinases (CK) and results in binding sites for calcium ions that subsequently play a key role during the initial stages of mineralization. Phosphorylation may also influence the secretion and extracellular organization of enamel proteins. Previous studies indicated that inositol hexasulphate inhibited the activity of CK-I and/or CK-II in mouse tooth germs (Torres-Quintana et al., 1998). We hypothesized that inositol hexasulphate would also inhibit the activity of the specific casein kinase(s) identified in secretory ameloblasts, and would prove useful for determination of the extent to which phosphorylation might influence the organization of enamel proteins at early stages of enamel formation. To test this hypothesis, we dissected mandibular first molars from 18-day-old mouse embryos and cultured them for 11 days in the presence of 0-0.1 mM inositol hexasulphate. Ultastructural analysis revealed that the formation of enamel was largely impaired at an inhibitor concentration > or = 0.08 mM. Quantitative radioautographic analysis of [33P]phosphate incorporation indicated that radiolabeled phosphate normally secreted into forming enamel was retained within ameloblasts. In contrast, no significant difference was observed between control and inositol-hexasulphate-treated tooth germs when cultures were labeled with [3H]serine and [3H]proline. SDS-PAGE and Western blot analysis confirmed that while inositol hexasulphate inhibited CK-mediated phosphorylation, it did not significantly alter protein synthesis. We conclude that impairment of phosphorylation leads to intracellular accumulation of [3H]phosphate-containing material by ameloblasts. We also conclude that when non-phosphorylated enamel matrix proteins are secreted, they are either unable to form an enamel matrix that supports mineralization, or they diffuse throughout a poorly mineralized dentin.

Ameloblasts↗
PubMed1999

A tyrosine kinase signaling pathway, regulated by calcium entry and dissociated from tyrosine phosphorylation of phospholipase Cgamma-1, is involved in inositol phosphate production by activated G protein-coupled receptors in myometrium.

Our experiments were conducted to evaluate, in rat myometrium, the potential contribution of a protein tyrosine kinase (PTK) pathway in the hydrolysis of phosphatidylinositol-4,5-bisphosphate mediated by bombesin, endothelin-1 (ET-1), and carbachol. The production of inositol phosphates (InsP) by agonists and AlF4- was partly inhibited (35-40%) by genistein and tyrphostins, two PTK inhibitors. Genistein attenuated uterine contractions elicited by the stimulation of muscarinic and bombesin receptors, whereas pervanadate, a protein tyrosine phosphatase inhibitor, potentiated receptor-mediated contraction. Tyrosine-phosphorylated proteins were detected in detergent extracts from agonist- and pervanadate-stimulated myometrium. The amount of InsP produced in response to pervanadate was related to the tyrosine phosphorylation status of phospholipase C-gamma1. In contrast, with ET-1 and bombesin, phosphorylated phospholipase C-gamma1 made a minor contribution. Additional findings were rather consistent with a role for Ca2+. In fura-2-loaded cells, genistein partly decreased both the transient and sustained intracellular Ca2+ concentration phases induced by bombesin. The removal of extracellular Ca2+ or the addition of nifedipine inhibited (35%) InsP production due to bombesin and ET-1. The inhibitory effects of genistein and tyrphostins were abolished in Ca2+-depleted medium, were not additive with that of nifedipine, and (as for nifedipine) were counteracted by the Ca2+ channel agonist Bay K 8644. The data are consistent with a PTK-mediated process in the activation of the voltage-gated Ca2+ influx that is involved in the production of InsP by stimulated G protein-coupled receptors.

Animals↗
PubMed1997

[Severe form of familial migraine with coma].

The authors report the case of a 43-year-old man experiencing a migraine attack with coma requiring a treatment in an intensive care unit for 9 days. The probable triggering cause as a cerebral arteriography.

Adult↗
PubMed1996

Pervanadate mediated an increased generation of inositol phosphates and tension in rat myometrium. Activation and phosphorylation of phospholipase C-gamma 1.

Stimulation of [3H]inositol-labeled rat myometrial strips with pervanadate, formed by mixing orthovanadate and H2O2, induced a dose-dependent accumulation of [3H]inositol phosphates. Orthovanadate or H2O2 added alone had no effect. Pretreatment of myometrium with two tyrosine kinase inhibitors, namely genistein and tyrphostin 47 (at 100 microM), reduced pervanadate-stimulated inositol phosphate formation by 50%. Pervanadate induced a time-sequential formation of inositol phosphates in the order inositol trisphosphate, inositol bisphosphate, and inositol monophosphate. The inhibitory effect of genistein was observed at the level of the three inositol phosphates. Pervanadate induced contraction of the myometrium; the response was dose-dependent. H2O2 or orthovanadate was without effect. Pervanadate-mediated contraction was inhibited (50%) by genistein and tyrphostin 47 (100 microM). Western blot analysis, using anti-phosphotyrosine antibodies, revealed that phosphorylated proteins were present in detergent extracts from pervanadate-stimulated myometrium. Tyrosine phosphorylation was reduced by a preincubation with 100 microM genistein or tyrphostin 47. Phospholipase C-gamma1 was immunodetected in myometrial extracts and was identified as one of the substrates subject to tyrosine phosphorylation following pervanadate treatment. The results demonstrate that, in myometrium, protein tyrosine kinase/phosphatase activities controlled both phosphorylation and activation of phospholipase C-gamma1, contributing to the modulation of the generation of inositol phosphates and tension.

Animals↗
PubMed1995

[Propofol and ketamine for dressing in burnt patients].

General anaesthesia is often required for burns dressing. Ketamine was the most common agent for carrying out removal of adherent dressings. Disadvantages are delirium on emergence from anaesthesia and prolonged recovery. We have studied an intravenous combination of propofol and ketamine in 29 burned patients for 39 dressings. After induction with 1 mg.kg-1 of propofol and 0.75 mg.kg-1 of ketamine, the maintenance rate was 2.5 mg.kg-1.h-1 of each agent. Satisfactory intraoperative conditions were obtained in all cases. Mean time of recovery was less than 15 min. Unpleasant dreaming occurred in 3 patients only, without agitation. The technique proved to be simple, effective and should revive interest for ketamine in the management of burned patients.

Adolescent↗
PubMed1995

[Lung contusion in the multiple trauma patient].

The main management's characteristics of the pulmonary contusion in the trauma patients are explained. From possible alveolocapillary membrane's injuries, with consideration of worsening evolution (ARDS, nosocomial infection, MOF), main points of discussion are circulation and mechanical ventilation. For the most severely injured, invasive monitoring is necessary, including the oxygenation parameters we now can dispose of. Quantification of extravascular lung water is an original and valuable tool to determine the time course and amount of pulmonary oedema. There is no ideal mode of ventilation but the basic ventilatory patterns must be adjusted; a target is the reduction of time requirement for ventilatory support.

Blood-Air Barrier↗
PubMed1994

[Acute silicosis caused by intentional inhalation of scouring powder].

A case of acute silicosis due to intentional inhalation of the scouring powder Ajax in a female patient suffering a sickle-cell trait (30% of S haemoglobin) is reported. It consisted of an acute immuno-allergic pneumonitis with fever and a respiratory distress syndrome. It was associated with a severe biological inflammatory syndrome and immunological disturbances with circulating immune complexes and antinuclear antibodies. The assessment of respiratory function demonstrated the presence of a restrictive syndrome with hypoxaemia and decreased CO transfer. The anatomopathological and mineralogical exams confirmed the diagnosis of silicosis and elicited birefringent particles in polarized light, some nodules, interstitial fibrosis and proteic deposits in favour of alveolar lipoproteinosis. The treatment included mechanical ventilation with PEEP, antibiotics and corticosteroids. Two pulmonary lavages were performed. The patient died of septic shock before a lung transplantation could be obtained.

Adolescent↗
PubMed1992

[Quality of sedation and neurologic evaluation following surgery of the posterior cranial fossa: the importance of propofol].

Following cerebral posterior fossa surgery, 23 patients were admitted in Intensive Care Unit for postoperative mechanical ventilation. Mean age was 45 +/- 16 years. Mean duration of surgical procedure was 09 h 20 min +/- 04 h 45 min. Heart rate, blood pressure, coma Glasgow scale, pupil reaction, respiratory pattern were recorded throughout the study. Following recovery from anaesthesia sedation was initiated by an intravenous bolus injection of propofol 2 mg.kg-1 followed by a continuous infusion starting at 1 mg.kg-1.h-1. The infusion rate was adjusted thereafter to ensure that the patient was sedated (Glasgow coma scale less than or equal to 6), unable to react to tracheal suction, well adapted to mechanical ventilation with a cardiovascular stability. Mean duration of sedation was 27 h 45 min +/- 04 h 45 min. Mean infusion rate of 3.81 mg.kg-1.h-1 allowed good sedation in 22 patients. There were no clinical changes in arterial pressure and heart rate. Propofol infusion was stopped transiently to assess neurologic status at 18 h +/- 02 h 45, 33 h 45 +/- 08 h 15, 49 h 10 +/- 16 h 50 after sedation onset. During these interruptions, the speed of recovery was assessed and arterial blood samples taken simultaneously. When the infusion was discontinued, adequate recovery was obtained in 48 +/- 26 min for 17 patients of 23, 64 +/- 58 min for 7 of 12, 70 +/- 65 min for 3 of 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗