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Biomedical subjects

M Gauthier

Publications and source records attributed to M Gauthier.

At least 73 records · Page 4Linked to original sources
PubMed1994

Effects of intracranial injections of scopolamine on olfactory conditioning retrieval in the honeybee.

The role of the cholinergic system on learning abilities and memory performance has been investigated in the honeybee. The behavioural experiment was the olfactory conditioning of the proboscis extension reflex, elicited by an antennal sucrose stimulation. Intracranial scopolamine (0.5 mg/kg) or saline injections (0.25 microliter) were given at different times before or after a one trial learning session in order to interfere with acquisition of information, storage or recall processes. Neither scopolamine injections, ranging from 20 min to 5 min prior to the acquisition task, nor post-trial drug injections given in the same time-window, impaired the retention performance measured one hour after conditioning. Scopolamine injected 20 min after a learning session induced a time-dependent decrease of information retrieval, as was seen in retention testing performed from 5 min to one hour after injection. Then, the amnestic effect of intracranial scopolamine injection seems to be related to a specific and temporary inhibition of recall processes. We can conclude that, in the present task, muscarinic-like receptors are involved in information retrieval but not in acquisition or consolidation processes.

Animals↗
PubMed1994

Admissions to a pediatric intensive care unit for status epilepticus: a 10-year experience.

OBJECTIVE: To characterize the etiology, course, and prognosis in children admitted to a pediatric intensive care unit (ICU) for status epilepticus. DESIGN: Retrospective, descriptive study. SETTING: Pediatric ICU in a university hospital. PATIENTS: One hundred forty-seven children admitted with status epilepticus. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Status epilepticus was defined as a prolonged (> 30 mins) or repeated tonic or tonic-clonic seizure with a persistent altered state of consciousness. Over 10 yrs, 147 children 0 to 16 yrs of age (median 1; mean 3.4 +/- 3.9 [SD]) were admitted to a pediatric ICU for, or with, 153 episodes of status epilepticus. Status epilepticus was caused most often by epilepsy (n = 52), atypical febrile convulsions (n = 21), bacterial meningitis (n = 20), encephalitis (n = 20), intoxication (n = 8), or a metabolic disorder (n = 12). Two infants, 1 and 3 months of age, and a patient with intoxication by isoniazid, responded to pyridoxine. Among 114 previously normal children, 34 patients displayed a new neurologic problem on discharge from the ICU, among whom, 68% (23/34) still had some neurologic abnormality 1 yr after the episode of status epilepticus. Nine patients died during their ICU stay, mostly from underlying disease rather than from the status epilepticus itself. A normal neurologic status before status epilepticus and age < 4 yrs seem to be markers of good prognosis, while encephalitis and meningitis appear to be markers for morbidity and mortality. CONCLUSIONS: Most cases of status epilepticus were caused by epilepsy, atypical febrile seizure, encephalitis, meningitis, or metabolic disease. The mortality rate during the ICU stay was 6%. The prognosis was good in most surviving cases, more so if the neurologic development of the child was normal before the status epilepticus.

Adolescent↗
PubMed1994

Timing and predictors of death in pediatric patients with multiple organ system failure.

OBJECTIVES: To describe the timing of onset of organ system failure, multiple organ system failure diagnosis, and the subsequent death in children admitted to a pediatric intensive care unit (ICU). Second, to identify independent risk markers of death in pediatric patients with multiple organ system failure. DESIGN: Review of a database. SETTING: Pediatric ICU within a tertiary care center. PATIENTS: We analyzed the pediatric ICU course of 777 consecutive patients aged < 18 yrs. MEASUREMENTS AND MAIN RESULTS: Eighty-five (10.9%) of 777 children had multiple organ system failure, defined as the simultaneous occurrence of at least two organ system failures. Of 85 children, 37 (43.5%) were postoperative cardiac surgery patients and 48 (56.5%) patients were in the ICU for other reasons. The diagnostic criteria for multiple organ system failure were met on the day of admission by 73 (86%) of 85 patients. The maximum number of organ system failures occurred within 72 hrs in 74 (87%) children. The mortality rate for all patients with multiple organ system failure was 50.6%. Thirty-eight (88.4%) of deaths occurred within 7 days after the diagnosis of multiple organ system failure. Survival analysis was comparable for both postoperative cardiac surgery patients and patients with other diagnoses. Multivariate analysis identified three factors as independent risk markers of death in pediatric patients with multiple organ system failure: maximum number of simultaneous organ system failures during the pediatric ICU stay: odds ratio, 55.9 (95% confidence interval, 7.9 to 396.1); age < or = 12 months: odds ratio, 17.1 (95% confidence interval, 1.8 to 158.7); and the Pediatric Risk of Mortality (PRISM) score on the day of admission: odds ratio, 1.25 (95% confidence interval, 1.1 to 1.5). CONCLUSIONS: The mortality rate associated with multiple organ system failure in pediatric patients is high. The maximum number of simultaneous organ system failures during pediatric ICU stay, age < or = 12 months, and the PRISM score on the day of admission are independent risk markers of death. Diagnosis of multiple organ system failures, development of maximum number of organ system failures, and deaths occur remarkably early after pediatric ICU admission; the rationale for using prophylactic therapy under such circumstances is unclear.

Adolescent↗
PubMed1994

Phylogenetic analysis and assessment of the genera Vibrio, Photobacterium, Aeromonas, and Plesiomonas deduced from small-subunit rRNA sequences.

We sequenced nearly complete small-subunit rRNAs of 54 reference strains belonging to the genera Vibrio, Photobacterium, Aeromonas, and Plesiomonas. We then performed a phylogenetic analysis by comparing the sequences which we obtained with all other known sequences for bacteria belonging to the gamma subgroup of the Proteobacteria (thus providing a data base consisting of 70 sequences for the genera investigated), using methods such as neighbor joining, maximum likelihood, and maximum parsimony, as well as bootstrap, to assess the robustness of each topology. Our results confirmed that the family Vibrionaceae should include only Photobacterium and Vibrio species (but not Vibrio marinus); that Aeromonas species deserve family rank; and that Plesiomonas shigelloides is linked to the family Enterobacteriaceae. The genera Vibrio, Photobacterium, Aeromonas, and Plesiomonas, together with the family Enterobacteriaceae, the family Pasteurellaceae, and probably the genus Alteromonas, form a robust monophyletic unit within the gamma 3 subgroup of the Proteobacteria.

Aeromonas↗
PubMed1993

Convulsions and hypertension in children: differentiating cause from effect.

OBJECTIVE: To determine if the magnitude of blood pressure (BP) increase could differentiate convulsion caused by a hypertensive crisis from a primary convulsive disorder, which itself increases BP. DESIGN: Retrospective analysis. SETTING: Admission to a pediatric intensive care unit (ICU) within a tertiary care center. PATIENTS: All children with hypertensive crisis admitted to the pediatric ICU from 1976 to 1990 were studied. Thirty-eight episodes occurred in 36 patients. The charts of children admitted for status epilepticus from 1976 to 1986 were also reviewed. One hundred and fifty-three episodes occurred in 145 patients. MEASUREMENTS AND MAIN RESULTS: BP values at entry to the pediatric ICU in patients with hypertensive crisis were compared with the highest BP values obtained within an hour after cessation of convulsion in 120 patients admitted for status epilepticus. The Z scores for BP, adjusted for age and sex, were compared. The BP values for children in hypertensive crisis with or without convulsions were by far greater than the BP values observed in patients in status epilepticus (p < .0001). For a patient in the postictal phase, a BP > or = 4.0 SD above the mean for age and sex predicted with 78% probability the presence of a hypertensive crisis requiring emergency treatment. If the BP was < 4 SD below the mean, the possibility of a hypertensive crisis was excluded (negative-predictive value 100%). CONCLUSIONS: Children with hypertensive crisis, as well as children with status epilepticus, can present with a high BP. In a postictal patient, the magnitude of BP increase is a useful clinical parameter to exclude a hypertensive crisis that requires specific treatment of the BP.

Adolescent↗
PubMed1992

Uvulitis and supraglottitis: early manifestations of Kawasaki disease.

Two children with Kawasaki disease initially had upper respiratory tract manifestations. The first was admitted with a diagnosis of uvulitis; in the second the clinical picture was characterized by supraglottic involvement, confirmed by direct laryngoscopic examination.

Child, Preschool↗
PubMed1992

Frequency of upper gastrointestinal bleeding in a pediatric intensive care unit.

OBJECTIVE: To determine the frequency of upper gastrointestinal (GI) bleeding in pediatric ICUs. DESIGN: Prospective, descriptive study. SETTING: Pediatric ICU in a university hospital. PATIENTS: All children admitted to a pediatric ICU over a 55-wk period. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Upper GI bleeding was considered to be present if there was an episode of hematemesis or if any amount of blood was seen in drainage from a nasogastric tube. Sixty-three (6.4%) upper GI bleeds were detected among 984 patients: 5.2% in 698 patients who did not receive upper GI bleeding prophylaxis, and 9.4% in 286 patients who did receive some prophylaxis. Density was defined as the number of events/1000 days.patient. The mean density was 10.8 GI bleeding episodes/1000 days.patient in a pediatric ICU. A multivariate analysis detected four independent risk factors or risk markers for upper GI bleeding: high Pediatric Risk of Mortality score, coagulopathy, pneumonia, and multitrauma. Age, sex, hepatic and respiratory failures were identified as confounding variables. An upper GI bleeding episode was defined as being clinically important if hypotension, death, or transfusion occurred within 24 hrs after the bleeding. There were four clinically important GI bleeding episodes. All were caused, at least in part, by a coagulopathy. The GI bleeding was associated with a need for transfusion in four children, and with hypotension in two. CONCLUSIONS: The frequency of upper GI bleeding is substantial, but the rate of occurrence of clinically important upper GI bleeding is low, even in a pediatric ICU where most patients do not receive any prophylaxis.

Adolescent↗
PubMed1992

Possible mediation by luminal somatostatin of bombesin-induced satiety in the cat.

Intravenous bombesin produced a dose-related stimulation of luminal gastric somatostatin output and a concomitant dose-dependent inhibition of food intake in the gastric fistula cat. Maximal food intake inhibition was observed at 1,280 pmol.kg-1.h-1 and corresponded to 65 +/- 7% (P less than 0.01). These effects of bombesin were dose dependently abolished by the specific bombesin-receptor antagonist, [Leu13-psi(CH2NH)-Leu14]bombesin. Furthermore, intragastric administration of somatostatin-14, at doses corresponding to those found in the gastric lumen in response to intravenously administered bombesin, significantly inhibited the first 30 min of food intake. This administration had however no effect on total (daily) food intake. We therefore suggest that luminal gastric somatostatin could at least account for bombesin-induced short-term satiety.

Animals↗