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Biomedical subjects

B Leduc

Publications and source records attributed to B Leduc.

At least 37 records · Page 2Linked to original sources
PubMed1984

Insulin-specific binding to erythrocytes in 6 girls with acanthosis nigricans.

6 girls, aged 4-16 years, with acanthosis nigricans and hirsutism were studied. Fasting and postglucose hyperinsulinism was present in the 5 older girls. In the youngest, a transitory diabetes with hyperinsulinism was induced by a cortisone therapy for hepatitis. Insulin resistance, suggested by the failure to significantly decrease blood glucose after insulin injection (0.1 U/kg), was demonstrated in three steps: (1) Patient plasma failed to bind 125I-insulin after a 5-day incubation followed by precipitation by antihuman globulin serum. (2) Specific 125I-insulin binding to rat liver membranes was identical in the presence of patient plasma and control plasma. (3) Specific 125I-insulin binding to the erythrocytes of the 6 patients (3.5-7.0%) was significantly lower (p less than 0.01) than in controls (4.5-19.5%). Moreover, the significant correlation present in controls between total binding and reticulocyte counts (r = 0.824, p less than 0.001) was absent in the patients. These data demonstrate further that, in the juvenile type of acanthosis nigricans, insulin resistance which may precede hyperinsulinism is not related to anti-insulin antibodies nor to antireceptor antibodies, but results from a primary defect of insulin receptors.

Acanthosis Nigricans↗
PubMed1982

The reproducibility of intrapartum cardiotocogram assessments.

Five obstetrician-gynecologists experienced in fetal monitoring assessed 150 intrapartum cardiotocograms obtained with an external transducer. There were three successive blind readings, the first two without any clinical data apart from gestational age. The reviewers indicated whether the tracings showed definite, possible or no abnormalities. The interpretations given by each reviewer for any one tracing were fairly consistent, but they varied markedly from one reviewer to another. The proportion of tracings interpreted as normal ranged from 39% to 74%, and the proportion assessed as abnormal ranged from 3% to 43%. All five observers agreed on the interpretation of 29% of the tracings. Inter-reviewer reproducibility scarcely changed when clinical data were provided. These findings emphasize the need to evaluate all methods of fetal monitoring before they become widespread.

Evaluation Studies as Topic↗
PubMed1982

Obstetrical profile of twin pregnancies: a retrospective review of 11 years (1969-1979) at Hôpital Notre-Dame, Montréal, Canada.

Four hundred and thirty-four twins delivered from 220 women at Notre-Dame Hospital were studied during a period of 11 years (1969-1979). The maternal, fetal, and neonatal outcome was compared before and after 1974, the year ultrasonography and other changes in perinatal care were introduced in our institution. Early diagnosis occurred more frequently after 1974, together with increased antenatal hospitalization. Preeclampsia and hepatic cholestasis occurred in 19.5% and 9.5% of women, respectively. Preterm delivery occurred in 42.2% of the cases. The corrected fetal mortality rate was 30.2/1,000 and corrected perinatal mortality rate was 74.9/1,000. About 90% of the neonatal deaths occurred in infants born before 36 weeks. Internal version and complete extraction of the second twin increased the neonatal mortality sixfold compared to spontaneous delivery. Availability of ultrasound examination significantly reduced preterm delivery.

Canada↗
PubMed1982

Perinatal profile of twin pregnancies: a retrospective review of 11 years (1969-1979) at Hôpital Notre-Dame, Montréal, Canada.

Four hundred and thirty four twins occurring in 220 women were studied during a period of 11 years (1969-1979) at Notre-Dame Hospital. Perinatal mortality (less than 28 days) was compared before and after 1974, and the impact of ultrasound technique upon perinatal outcome was assessed during the second period (1974-1979). The main factor associated with perinatal mortality was low birth weight caused by either prematurity or intrauterine growth retardation. While fetal mortality remained unchanged within the two study periods, neonatal mortality decreased from 68.2/1,000 to 28.9/1,000 mainly due to increased survival rate of twins below 1,500 g at birth. With identical perinatal care during the same period, perinatal mortality and incidence of intrauterine growth-retarded twins remained unchanged despite early diagnosis by ultrasound.

Canada↗
PubMed1982

[Plasma sulfation and thymidine activities in diabetic children and adolescents].

Sulfation and thymidine activities were measured in 14 insulin-treated diabetic children aged 4 to 16 years. Mean plasma sulfation activity was 0.86 +/- SEM 0.09 U/ml, values being highly significantly negatively correlated with Hb A1c (r = 0.663, p less than 0.01) and with 24 hours glucosuria (r = 0.764, p less than 0.001). Mean plasma thymidine activity was 1.04 +/- SEM 0.09 U/ml) but not with the other parameters. No relationship was found between sulfation and thymidine activities and insulin concentrations in the same samples. Additionally mean plasma transferrin concentration was 2.732 +/- SEM 0.152 U/ml, not significantly different from normal values. These data demonstrate that, in diabetic children treated by insulin, sulfation factor level is closely correlated to the quality of the control of the metabolic disorder. In contrast, thymidine activity of plasma appears to be unaffected by the level of glycemic regulation.

Adolescent↗
PubMed1980

Acro-renal-mandibular syndrome.

We report two female sibs, with severe split-hand/split-foot malformation associated with renal and genital anomalies. The patients also have severe mandibular hypoplasia and some other, minor anomalies. The relationship to the acro-renal "syndrome" in particular and to other phenotypes with similar malformations in general is discussed. Because of consanguinity in the parents, autosomal recessive inheritance seems likely. However, the presence of a septate uterus in the mother and a double collecting system in the only living sib could also suggest possible dominant inheritance with variable expressivity.

Consanguinity↗
PubMed1975

Cardiovascular changes associated with fetal breathing.

Studies were carried out on seven fetal lambs, 3 to 1 weeks prior to the expected date of delivery to determine if, during fetal breathing, cardiovascular events were similar to those described as occurring with respiration after birth. The following changes were observed; (1) a slight decrease in pressures with the initiation of the rapid inspiratory movements followed by: (2) a marked elevation of the systolic and diastolic pressures; (3) a cyclic variation characterized by a fall in arterial pressure with inspiration; (4) a variable acceleration of the heart rate; and finally, (5) a typical respiratory arrhythmia. These findings demonstrated that, during fetal respiratory movements, there are some cardiovascular changes which are specific to this period of life. There are other changes which are identical to what has been observed after birth. These latter cardiovascular changes imply that the endotracheal pressure variations are the reflection of authentic inspiratory movements under the influence of the central nervous system.

Animals↗
PubMed1972

The effect of hyperventilation on maternal placental blood flow in pregnant rabbits.

1. In anaesthetized pregnant rabbits near term, cardiac output and its distribution were measured by injection of isotope-labelled microspheres. Hypocapnia (mean arterial P(CO) (2) 18 mm Hg), induced by intermittent positive pressure hyperventilation, caused a 43% reduction in maternal placental blood flow, attributed mainly to vasoconstriction. Myometrial flow was not significantly changed.2. Moderate hypercapnia (mean arterial P(CO) (2) 46 mm Hg) caused no change in placental flow, compared with observations made while breathing air spontaneously (P(CO) (2) 31 mm Hg).3. Intravenous infusions of adrenaline or noradrenaline 1 mug/kg. min caused maternal placental vasoconstriction.4. During the especially warm summer of 1969, there was a mean 46% reduction in maternal placental blood flow in pregnant rabbits near term, breathing room air spontaneously with normal blood gas values and rectal temperatures. This was associated with an increase in the number of runts and dead foetuses.

Animals↗