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Biomedical subjects

H Bard

Publications and source records attributed to H Bard.

At least 55 records · Page 3Linked to original sources
PubMed1988

Outcome at school age of children with birthweights of 1000 grams or less.

A follow-up study was done of extremely low-birthweight infants (less than or equal to 1000g) born between 1976 and 1979, a period when aggressive intervention was not routine practice. The survival rate was 19 per cent. 44 of the 46 survivors were followed to a mean age of 6 1/2 years. By five years of age 23 of the 44 children had been admitted to hospital, mainly for surgery and respiratory problems. Eight of 31 five-year-old children were growth-retarded and five of 26 were microcephalic. Among 44 children, ophthalmological problems were found in nine cases and neurosensory impairments (cerebral palsy, deafness) in seven. 12 children were mentally handicapped or had impaired intelligence (IQ or DQ less than 85). Over-all, 14 of the 44 children had impairments, severe in four cases and moderate in 10. Mean verbal IQ was significantly lower than mean performance IQ. Among 37 children in school or in remedial programs, nine required special education and another 12 in regular classes either failed or had very poor results, or needed extra professional help. Only 16 of the children had no significant problems in school. These findings indicate that extremely low birthweight (less than or equal to 1000g) represents a major risk to life, health (hospital admissions), long-term growth, neurosensory integrity, cognitive development and learning potential.

Child↗
PubMed1988

Effect of indomethacin on cerebral blood flow velocity of premature newborns.

Using the Doppler technique, the effect of therapeutic doses of indomethacin on the cerebral blood flow velocity (CBFV) of anterior cerebral arteries was studied in 13 preterm infants with patent ductus arteriosus. The first intravenous injection of indomethacin (0.2 mg/kg, group 1, n = 10) induced a significant decrease in the area under the velocity curve at 15 min (-22%), which was sustained until 120 min (-28%, p less than 0.005). In contrast, no significant change in CBFV occurred after the third dose (group 2, n = 7). In both groups, capillary blood gases, mean arterial blood pressure, and heart rate remained stable throughout the study. In 5 mechanically ventilated infants, the increase in CBFV secondary to suctioning was significantly attenuated after the first dose of indomethacin (p less than 0.02) but not after the third (p = 0.56). Thus, an initial dose of indomethacin may attenuate CBFV increases secondary to clinical manipulations in the preterm newborn.

Apgar Score↗
PubMed1988

The inhibition of the postnatal rise of 2,3-diphosphoglycerate in newborn lambs as a result of glucose perfusion.

Due to the abrupt increase in 2,3-diphosphoglycerate (2,3-DPG) concentration in the newborn lamb, which begins soon after birth, this interval in development was considered an excellent period to test the hypothesis that glucose perfusions could inhibit 2,3-DPG synthesis. Ten newborn lambs were divided into two groups and perfused either with glucose (15 mg/kg/min) or physiologic saline (45% NaCl) for 10 days. Blood gases, electrolytes, glycemia, O2 pressure at 50% Hb saturation, and 2,3-DPG levels were compared in the two groups. Glucose levels remained significantly elevated during the first 3 days in the glucose perfused group. The O2 pressure at 50% Hb saturation increased in both groups but was significantly lower in the glucose perfused group when determined on day 5 and 8. The postnatal increase in 2,3-DPG was significantly diminished in the glucose infused lambs, which suggests that glucose perfusion has an inhibiting effect on erythrocyte 2,3-DPG synthesis.

2,3-Diphosphoglycerate↗
PubMed1987

Cardiovascular status during ketamine anesthesia in the fetal lamb.

To determine the effects of maternal ketamine anesthesia on fetal hemodynamic and cardiac function, a study was carried out on 8 chronically catheterized fetal lambs. Ketamine was administered intravenously to the mother every 15 min during 1 h. The fetal PO2 and pH remained within physiological limits whereas the PCO2 decreased from 44.35 +/- 1.36 to 37.32 +/- 4.75 Torr (p less than 0.05). The following changes of the fetal heart systolic time intervals were observed: a progressive lengthening of the preejection period (PEP) (from 52 +/- 10 to 63 +/- 11 ms, p less than 0.01), a shortening of the ejection time (ET) and a significant increase of the PEP/ET ratio (from 0.32 +/- 0.04 to 0.47 +/- 0.01, p less than 0.01). The two components of PEP, electromechanical delay and the isovolumetric contraction time were both prolonged. A progressive rise of fetal systolic and diastolic pressures was also noted (p less than 0.01). Fetal heart rate increased (145 +/- 33 to 190 +/- 28 beats/min, p less than 0.01) and cardiac beat-to-beat variability decreased (from 0.028 to 0.009, p less than 0.01) during the ketamine anesthesia. This study demonstrates that maternal anesthesia with ketamine can alter indices of fetal myocardial function and other cardiac parameters used in fetal and neonatal monitoring, without affecting tissular oxygenation.

Anesthesia, General↗
PubMed1987

[Papular mucinosis. Associated dermatologic and dysimmune aspects].

Papular mucinosis (PM) is an overload disease mostly made of proteoglycans, essentially cutaneous and accompanied with a monoclonal gammapathy. In addition to the cutaneous lesions, vascular and neurological manifestations may be responsible for severe complications. The gammapathy, most often benign, does not seem always correlated with the skin involvement. We report the case of a patient with mucinosis associated with a rheumatoid polyarthritis, then with a systemic necrotizing angiitis. A review of the literature has enabled us to notice the frequency with which PM is accompanied with dysimmune diseases, especially lupus.

Adolescent↗
PubMed1986

Myocardial function and hemoglobin oxygen affinity during hyperglycemia in the fetal lamb.

To determine the effects of maternal hyperglycemia on fetal hemodynamic and cardiac function, a study was carried out on nine chronically catheterized fetal sheep. In six fetuses, glucose was infused intravenously with an initial dose of 5 mg/kg per min. Data were compared with controls. This dose was gradually increased to 16 mg/kg per min by the fifth day. The initial blood glucose was 14.7 +/- 3.0 mg/dl and increased to 54.6 +/- 16.4 mg/dl by the last day of the infusion period (P less than 0.001). The PO2 decreased from a baseline of 20.25 +/- 3.40 to 15.88 +/- 5.24 mmHg (P less than 0.01). Similarly significant decreases were also observed for the blood O2 content and O2 hemoglobin saturation: 8.5 +/- 1.7 to 6.4 +/- 2.2 ml/dl and 62.3 +/- 13.6 to 46.1 +/- 17.6%, respectively, during hyperglycemia (P less than 0.01). The duration of the preejection period (PEP) before the start of the experiment was 45 +/- 4 ms; a final value of 57 +/- 10 ms was obtained (P less than 0.01). However, the electromechanical delay and ejection time (ET) showed no significant variation. The ratio of the PEP/ET increased from 0.31 +/- 0.04 to 0.38 +/- 0.07 (P less than 0.01) during hyperglycemia. The reticulocytes increased from 1.4 +/- 1.8 to 3.1 +/- 2.9% (P less than 0.05) and the 2,3-diphosphoglycerate decreased from 4.4 +/- 1.1 to 2.8 +/- 1.2 mumol/g hemoglobin (P less than 0.005). This study demonstrated that fetal hyperglycemia depresses myocardial function in the fetal lamb. The changes in cardiac function could not be explained by the small drop in O2 saturation.

2,3-Diphosphoglycerate↗
PubMed1985

Effects of maternal alcohol intoxication on fetal circulation and myocardial function: an experimental study in the ovine fetus.

To determine whether acute alcohol ingestion during pregnancy could affect fetal myocardial function, studies were carried in six chronically catheterized fetal sheep during maternal alcohol infusion. Absolute ethyl alcohol (0.8 ml/kg) was administered to the mother over 10 minutes via the jugular vein. These infusions were repeated every 30 minutes during 3 hours, and peak maternal and fetal blood concentrations close to 200 mg/dl alcohol were reached. Fetal PCO2 decreased from a baseline of 43.15 +/- 3.75 to 36.13 +/- 2.6 torr 1 hour after the start of alcohol infusion (P less than 0.05). Similarly, pH rose from 7.37 +/- 0.027 to 7.44 +/- 0.015 (P less than 0.05). Both values returned to baseline level at the end of alcohol infusion. PO2 remained within physiologic limits. The systolic time intervals of the fetal heart showed a rapid and prolonged modification. The pre-ejection period from 58 +/- 8 to 66 +/- 4 msec (P less than 0.05) during the infusion; this change was related to an increase in the isometric contraction period. The ratio of the pre-ejection period over the ejection time was also significantly increased (P less than 0.01), and remained elevated until the end of the experiment (12 hours). A rise in fetal systolic and diastolic pressures was observed at about 2 hours after the start of the alcohol infusion, and lasted 4 hours. This study suggests that an episode of maternal alcohol intoxication causes rapid depression of fetal myocardial contractility that is maintained several hours after cessation of alcohol ingestion.

Alcoholic Intoxication↗
PubMed1985

Physiologic modulations of the systolic time intervals in the fetal lamb.

To examine the modulation of fetal systolic time intervals of the ovine fetus in relation to fetal maturation, heart rate, respiratory activity, and circadian rhythm, studies were carried out on 13 fetal-maternal sheep preparations. The data obtained showed that there was a significant correlation between the ejection time (ET) and the RR intervals of the electrocardiogram. The pre-ejection period (PEP) and PEP/ET increased in relation to the fetal maturation (38 ms and 0.25 at 120 days to 52 ms and 0.33 at 145 days of gestation, respectively). When the circadian rhythmicity was analyzed, a relative tachycardia was in evidence during the 21- to 03-h period but systolic time intervals remained unchanged. Except for some tachycardia and cardiac rhythm variability, respiratory activity also had no influence on the systolic time intervals.

Animals↗
PubMed1985

Circulatory changes in newborn lambs with experimental polycythemia: comparison between fetal and adult type blood.

Hemodynamic effects of increased hematocrit were compared in two groups of newborn lambs. In the first group (fetal type blood), exchange transfusions were carried out using packed red blood cells obtained from newborn lambs within one to two hours after birth. In the second group (adult type blood), the same procedure was carried out using adult sheep blood. In both groups, hematocrit values ranging between 70% and 80% were reached. The increase in hematocrit caused a decrease in cardiac output due to an increase in peripheral resistance. Pulmonary resistance increased more than systemic resistance. However, the increase in pulmonary resistance was significantly greater in the polycythemic newborn lambs with adult blood. A right-to-left shunt through a patent ductus or a foramen ovale was noted in six of the eight lambs included in this group. On the other hand, none of the seven polycythemic newborn lambs with fetal blood developed signs of right-to-left shunting. It is concluded that during neonatal polycythemia, the level of hematocrit is not the sole factor responsible for the hemodynamic changes observed. Other unknown influences related either to the red cells or the plasma must impinge upon the pulmonary circulation to alter vascular resistance.

Animals↗
PubMed1985

Relative rates of fetal hemoglobin and adult hemoglobin synthesis in cord blood of infants of insulin-dependent diabetic mothers.

Erythrocytosis, extramedullary erythropoiesis, and increased levels of plasma erythropoietin have been observed in newborn infants of diabetic mothers. Because there is evidence that there is a relationship between increased fetal hemoglobin production and acute erythropoietic expansion, it was considered important to study the proportion of fetal hemoglobin and adult hemoglobin synthesis in newborn infants of insulin-dependent diabetic mothers. Samples from nine newborn infants of diabetic mothers as well as nine control infants, ranging from 36 to 38 weeks of gestation, were incubated in an amino acid mixture containing [14C]leucine. The adult hemoglobin and fetal hemoglobin were then separated by column chromatography on DEAE [O-(diethylaminoethyl)] Sephadex. To confirm that the fetal hemoglobin obtained after Sephadex chromatography was not contaminated with other hemoglobins, several of the DEAE separations from each group were reconstituted and subjected to polypeptide chain elution using carboxyl-methyl cellulose chromatography. The data demonstrated that the newborn infants of diabetic mothers are synthesizing significantly more fetal hemoglobin than is expected for their period of development (82.2 +/- 3.6 v 72.8 +/- 4.2; P less than .005). It is suggested that the in utero environment of the fetus of the diabetic mother causes an increase in fetal hemoglobin synthesis.

Diabetes Mellitus, Type 1↗
PubMed1984

The difference between the systolic time intervals of the left and right ventricles during fetal life.

In order to determine if the two ventricles of the fetal heart contract synchronously the systolic time intervals of both ventricles were compared. Eight experiments were carried out on fetal lambs. The studies demonstrated that while the ejection times of both ventricles were the same, the mean pre-ejection period of the right ventricle was significantly greater than that of the left (57 +/- 8 versus 48 +/- 8 msec, p less than 0.005). These findings were further substantiated in serial studies during a 7-day period on the same fetal lamb. If changes in the systolic time intervals are to be useful in evaluating fetal myocardial function, the values should be obtained from the same ventricle.

Animals↗
PubMed1984

[Sterno-chondro-costal joint arthritis in heroin addicts. Value of computed x-ray tomography. 4 cases].

Four cases of sterno-articular arthritis in young heroin addicts are reported. The diagnosis, much facilitated by the knowledge of drug addiction, is confirmed by biopsy which excludes a tumour, usually malignant in that region. Computerized tomography is essential to explore for retrosternal extension. In the absence of extension cure can be obtained by medical treatment, thus avoiding resection of the sternum and rib with subsequent plastic surgery.

Adult↗
PubMed1984

Tumoral calcinosis: light and electron microscopic study with electron diffraction and x-ray microanalysis of the mineral deposit.

Samples of deposits taken from sites close to articulations in a young black African suffering from tumoral calcinosis with hyperphosphoraemia were studied by light and electron microscopy techniques. Light microscopy demonstrated lesions of a foreign body granuloma type in contact with calcium salt deposits suggesting that the process was of an active nature. Electron microscopy, and the demonstration of acid phosphatase activity, led to the identification of two cell types: mono or multinuclear macrophage type cells which phagocytose the deposit, and fibroblastic type cells. No signs of damage to the microvessels or the interstitial collagen were noted which could serve as a basis or a physiopathological explanation of the deposition. The deposits were analysed by energy dispersive X-ray microanalysis and by electron diffraction and were considered to be hydroxyapatite.

Acid Phosphatase↗
PubMed1984

Value of systolic time intervals in the diagnosis of large patent ductus arteriosus in fluid-restricted and mechanically ventilated preterm infants.

M-mode echocardiographic features suggesting a patent ductus arteriosus are based on two groups of indirect criteria: dilation of the left cardiac cavities and changes of systolic time intervals. The reliability of the first group of criteria has been questioned in fluid-limited, mechanically ventilated preterm infants. The sensitivity of the systolic time intervals in the same circumstances is investigated. Twenty-three patients with a large patent ductus arteriosus were selected. Review of their echocardiograms shows that the sensitivity of the various criteria (expressed as percentage of positivity) was as follows: inversion of the ratio of left ventricular preejection period to right ventricular preejection period, 91.3%; left ventricular preejection period to left ventricular ejection time over right ventricular preejection period to right ventricular ejection time less than 1,83%; left atrium dilation, 74%; shortening of left ventricular preejection period, 70%; dilation of left ventricular internal dimensions in diastole, 65%; increase in left atrium/aorta, 52%; and decrease of left ventricular preejection period to left ventricular ejection time, 48%. Three criteria involving time intervals (left ventricular preejection period to right ventricular preejection period, left ventricular preejection period, and left ventricular preejection period to left ventricular ejection time) had 100% specificity. The lowest specificity was found with criteria involving the left atrium (left atrial to aortic root ratio 75% and left atrium 63%). It is concluded that study of systolic time intervals is a reliable means of detecting preterm infants with hemodynamically significant left-to-right shunt through a patent ductus arteriosus even if the infants are mechanically ventilated and fluid restricted.

Ductus Arteriosus, Patent↗
PubMed1984

Low levels of blood alcohol and fetal myocardial function.

In ten experiments carried out on five chronically catheterized pregnant ewes (130 to 140 gestational days), 0.8 ml/kg absolute ethyl alcohol was injected into the mothers over a ten-minute period. Peak maternal and fetal alcoholemia levels were 1.1 +/- 0.1 and 0.9 +/- 0.04 g/L, respectively. Blood gases (arterial PO2, PCO2, pH, and arterial O2 content), cardiovascular parameters (heart rate, arterial pressures), and fetal myocardial function (systolic time intervals) were studied at basal state and during the four hours after injection. To observe changes in fetal O2 affinity, 2-3 diphosphoglycerate concentration and P50 were assessed before and at the peak of blood alcohol level. Maternal and fetal blood ethyl alcohol levels correlated closely (r2 = 0.9512) during all experiments. A small increase in the fetal arterial pH and a decrease in maternal PCO2 was observed just after the injection. This low level of fetal blood alcohol caused a moderate but significant decrease in myocardial contractility as judged by the changes in systolic time intervals. There was no alteration of other cardiovascular parameters and of hemoglobin oxygen affinity.

Animals↗
PubMed1984

[Phosphorus metabolism in a case of tumoral calcinosis].

Hyperphosphataemia with levels of 65 mg/l was found in a black African aged 20 with a 10-year history of tumour calcinosis. Levels of blood calcium, plasma ionised calcium, serum alkaline phosphatase, 24-hour urinary calcium and phosphate were all normal, as was renal function. Tubular phosphate reabsorption (TmP) was greater than 90 mg per litre of glomerular filtrate (N = 22-42). Levels of circulating parathyroid hormone, nephrogenic cAMP and serum vitamin D metabolites [25 OH D3, 24,25 (OH)2 D3 and 1,25 (OH)2 D3] were normal. The TmP fell by 36% on exogenous PTH stimulation (N = 30.25 +/- 6.7), and by 7.9% 120 min. after injection of acetazolamide. Our results confirm the conclusions of recent studies: patients with tumour calcinosis have disordered renal phosphate excretion with normal PTH secretion, normal PTH action on the renal tubule and normal vitamin D metabolism. In fact in these hyperphosphataemic patients, circulating 1,25 (OH)2 D3 levels would be expected to be low, whereas they were normal in our patient. An attempt at treatment with acetazolamide and phosphate chelating agents gave no significant results.

Acetazolamide↗