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Biomedical subjects

R Sauve

Publications and source records attributed to R Sauve.

10 recordsLinked to original sources
PubMed1999

Two-year survey of Alberta laboratories processing of antenatal group B streptococcal (GBS) screening specimens: implications for GBS screening programs.

We evaluated specimen types received and methods used by laboratories to process screening GBS specimens from pregnant women. Surveys during 1995 and 1997 of all laboratories in the province of Alberta, Canada that culture GBS from screening genital specimens were completed. Between surveys, there was dissemination of information about appropriate culture techniques. Survey completion rates were 100% in both years (38/38 in 1995 and 20/20 in 1997). During 1995 as compared to 1997, laboratories were less likely to a) have a specific written protocol for identification of genital GBS screening specimens (1995: 78.2% versus 1997: 100%, p = 0.08) b) be receiving combined vaginal-anorectal swabs (1995: 18% of all swabs received versus 1997: 60.4%, p < 0.001), and c) be using selective GBS culture media (1995: 45.5% versus 1997: 86.7%, p = 0.01). Regions using screening based approaches for GBS prevention need to ensure that their laboratories are using adequate techniques for GBS detection.

Alberta↗
PubMed1995

Double-blind 1-year follow-up of 1540 infants with respiratory distress syndrome randomized to rescue treatment with two doses of synthetic surfactant or air in four clinical trials. American and Canadian Exosurf Neonatal Study Groups.

Synthetic surfactant has been shown to reduce neonatal and 1-year mortality and neonatal morbidity in infants with respiratory distress syndrome. However, less is known about the effects of synthetic surfactant on developmental outcome and long-term morbidity. Four multicenter, randomized, placebo-controlled trials of synthetic surfactant administered as rescue therapy were conducted in the United States and Canada, with a total enrollment of 2224 patients. Double-blind developmental evaluations of survivors were conducted at 1 year of age (adjusted for prematurity) in all four trials. Of the 1802 patients enrolled in the placebo-controlled rescue trials who survived to 1 year, 1540 (85%) completed the 1-year follow-up evaluation. Height, weight, and head circumference measurements were not different in the treatment and control groups. Mean and median Bayley Scores of Infant Development for both the Mental Development Index and the Psychomotor Development Index were also equivalent. The incidence of impairments was not different in the two groups (mild to moderate impairment, 12% (92 of 745) for the air placebo group vs 11% (86 of 771) for the synthetic surfactant group; severe impairment, 15% (114 of 745) for the air placebo group vs 13% (102 of 771) for the synthetic surfactant group). No differences in rates of retinopathy of prematurity or hearing impairment were found in the treatment groups. The need for surgery after day 28 of life (relative risk, 0.779; 95% confidence interval, 0.665, 0.927) and the need for respiratory support at 1 year (relative risk, 0.525; 95% confidence intervals, 0.303, 0.911) were both reduced in the synthetic surfactant group. These results indicate that developmental outcome at 1 year of age is at least as good among infants with respiratory distress syndrome who received rescue therapy with synthetic surfactant as it is in infants who received air placebo; the results also indicate that the incidence of long-term morbidity is reduced.

Air↗
PubMed1995

Outcome at 1-year adjusted age of 957 infants weighing more than 1250 grams with respiratory distress syndrome randomized to receive synthetic surfactant or air placebo. American and Canadian Exosurf Neonatal Study Groups.

This study determined outcomes at 12-months adjusted age of 957 infants weighing more than 1250 gm at birth who were subjects in a randomized, double-blind, controlled trial of synthetic surfactant or air placebo administered in a rescue trial at 23 hospitals in the United States and 13 hospitals in Canada. Follow-up results were available for 475 of 563 surviving infants who received air placebo (84%) and 482 of 571 infants who received synthetic surfactant (84%). Developmental outcome was equivalent in the two groups. Morbidity was less in the synthetic surfactant group as assessed by the need for medication for chronic lung disease (52 of 475 (11%) for the air placebo group vs 32 of 482 (7%) for the synthetic surfactant group) or respiratory support (10 of 475 (2%) for the air placebo group vs 1 of 482 (< 1%) for the synthetic surfactant group) at 1-year adjusted age. Bayley Scales of Infant Development (mental development Index: 102 for both the air placebo and synthetic surfactant groups; psychomotor development index: 95 for the air placebo group vs 94 for the synthetic surfactant group) and impairment rates (94 of 475 (20%) for the air placebo group vs 86 of 482 (18%) for the synthetic surfactant group) were similar in the two groups. Infants weighing more than 1250 gm who have respiratory distress syndrome have previously been shown to have improved survival rates and lower neonatal morbidity after treatment with synthetic surfactant. These follow-up data confirm that developmental outcome as determined at 12-months adjusted age is at least as good in those receiving synthetic surfactant.

Air↗
PubMed1993

Spinal cord injury at birth: diagnostic and prognostic data in twenty-two patients.

OBJECTIVES: To establish criteria, evident soon after birth, that predict long-term outcome of neonates with spinal cord injury (SCI) at birth. DESIGN: Retrospective case-series. SETTING: Five Canadian regional neonatal tertiary care centers. PATIENTS: Consecutive samples of patients referred to five centers for a total of 22 subjects, in whom SCI was diagnosed during life. Sites of lesions were above the fourth cervical vertebrae (n = 14), at the fourth cervical to the fourth thoracic vertebrae (n = 6), and at the thoracolumbar region (n = 2). MEASUREMENTS AND MAIN RESULTS: All 14 patients with upper cervical SCI had cephalic presentations, whereas all 6 patients with cervicothoracic SCI had breech presentations (p < 0.0001). The site and extent of lesion were best diagnosed by clinico-imaging correlations. Ultrasonography appeared to be the most useful imaging study. In patients with upper cervical SCI who had no coexistent central nervous system abnormality associated with early death, long-term outcome in survivors (dependency on mechanical ventilation and on aids for upper limb activity and for ambulation) was best predicted by age when breathing was first observed and by rate of recovery of limb motor function in the first 3 months. The presence of breathing movements on day 1 (n = 2) was associated with mild disability. The absence of breathing movements on day 1 and little or no recovery of motor function in the first 3 months was associated with permanent total dependency on mechanical ventilation and severe quadriplegia (n = 5). Apnea on day 1 and intermediate recovery rates in the first 3 months was associated with variable long-term prognoses (n = 3).

Birth Injuries↗
PubMed1991

A randomized controlled trial of early amniotomy.

OBJECTIVE-To determine if a policy of early amniotomy resulted in a reduction in mean labour duration when compared to a policy of conservation of the membranes. DESIGN-A single-centre randomized controlled trial. SETTING-A tertiary care teaching hospital in Alberta, Canada. SUBJECTS-Ninety-seven term nulliparae in spontaneous labour, baby in cephalic presentation. INTERVENTION-Early amniotomy versus intent to keep membranes intact. MAIN OUTCOME MEASURES-Interval from randomization to delivery, rate of abnormalities of fetal heart rate tracings, cord artery blood pH, Apgar scores. RESULTS-The mean interval from randomization to delivery was 390.9 (SE 29.1) min in the amniotomy group and 442.9 (SE 34.1) min in the control group (P = 0.251). There were no differences between groups in the occurrence of fetal heart rate tracing abnormalities, nor was there a difference in the proportion of babies with abnormal Apgar scores, or abnormal cord pH (less than 7.20). CONCLUSION-The results of the study fail to support the long held belief that early amniotomy is an effective method for reducing labour duration.

Amnion↗
PubMed1988

External ATP triggers a biphasic activation process of a calcium-dependent K+ channel in cultured bovine aortic endothelial cells.

We have used the patch-clamp method in order to investigate the single-channel events underlying the effect of external ATP on the potassium permeability of bovine aortic endothelial cells (BAE). The results obtained from cell-attached and inside-out experiments led first to conclude that BAE cells possess an inward rectifying potassium channel activated by internal calcium at micromolar concentrations. The channel conductance for inward currents was estimated at 40 pS in symmetrical 200 mM KCl and the open-channel probability was found to be voltage insensitive within the membrane voltage range -50 to -100 mV. Based on results obtained in the cell-attached configuration, it could next be established that external ATP and ADP at micromolar concentrations could trigger, via the stimulation of P2 purinergic receptors, a time variable activation process of the observed calcium-dependent potassium channel. This activation process was found to occur in a biphasic manner with an initial phase independent of the presence of calcium in the cell bathing medium. The second phase which could be blocked by calcium channel blockers such as Co2+ or La3+ required, however, the presence of external calcium and could be abolished by depolarizing the cells using high K+ external solutions. Another important aspect related to this phenomenon was the observation that removing ATP from the external medium during the second phase led to a complete abolition of the associated calcium-dependent potassium channel activation process. It is suggested from these results that the action of ATP on the potassium permeability of BAE cells is related to a second messenger mediated release of calcium from internal calcium stores coupled to an ATP-dependent calcium influx abolished at depolarizing voltages.

Adenosine Triphosphate↗
PubMed1988

Pulmonary hypoplasia testing in clinical obstetrics.

An ultrasound-based diagnostic test for predicting pulmonary hypoplasia antenatally by measurements of fetal chest circumference was applied prospectively to 45 patients at risk for developing this disorder. The outcome for the newborn infant and the autopsy findings were correlated with the antenatal prediction. The results of this test demonstrated a sensitivity and a specificity of 88% and 96%, respectively. The application of this test to clinical practice is recommended.

Amniotic Fluid↗
PubMed1978

Surface potential of phosphatidylserine monolayers. I. Divalent ion binding effect.

Surface potentials of phosphatidylserine monolayers have been measured in the presence of different divalent ion concentrations in order to determine the way in which divalent ions bind to the membrane surface. The association constants for divalent ions (Mg2+, Ca2+ and Mn2+) with the phosphatidylserine membrane have been obtained from the experimental data and simple ion binding theory. The order of divalent ion binding to the membrane is Mn2+ greater than Ca2+ greater than Mg2+. However, none of the divalent ions used completely neutralized the negative charge of phosphatidylserine even at relatively high concentrations. The amounts of the divalent ions bound depended upon the concentration of the monovalent ions present in the subphase. It is suggested that the amounts of bound ions obtained from the use of radioisotope tracer methods may include a considerable contribution from the excess free ions in the double layer region of the phosphatidylserine membrane.

Binding Sites↗