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Biomedical subjects

B L Salle

Publications and source records attributed to B L Salle.

At least 19 recordsLinked to original sources

An analysis of the microbial flora of premature neonates.

An analysis of the microbial flora of 10 premature neonates hospitalized in a neonatal intensive care unit (NICU) was made. The babies had received neither antibiotics nor antiseptics and nine out of 10 were born by caesarean section. Samples were collected on the fourth or fifth day of life from 18 skin or mucosal sites. Detailed bacterial counts were obtained by plating out suitable dilutions of the samples on to selective media. Representative samples of each colony type were then subcultured and identified, using standard laboratory methods. Two hundred and fifty-six isolates of staphylococci were obtained and their susceptibility to 23 antibiotics tested. Only 11% of the samples were sterile. Coagulase-negative staphylococci (CNS) were the commonest species isolated and were predominant in every site studied. They were found in 79% of the samples and represented almost 81% of the neonates' flora. Eight species and biotypes of CNS were identified. In decreasing order of frequency, they comprised S. epidermidis (biotypes 1 and 2), S. hominis (biotype 1), S. warneri, S. haemolyticus, S. capitis, S. cohnii and S. hominis (biotype 2). CNS distribution appeared to be highly heterogeneous with no significant specificity of any species for a particular body site. The main quantitative and qualitative variations seemed to relate to the method of delivery, and the intensity and nature of exposure of the neonate to its local environment. A high level of antibiotic resistance was found among the CNS isolates (especially S. epidermidis and S. haemolyticus): penicillin G (96%), oxacillin (31%), erythromycin (52%) and gentamicin (28%). Moreover, multiresistant strains were numerous, supporting the nosocomial origin of CNS.

Bacterial Typing Techniques

Net calcium absorption in premature infants: results of 103 metabolic balance studies.

Net calcium absorption was evaluated in 103 low-birth-weight preterm infants by a 72-h balance technique. At birth the infants had a mean (+/- SE) gestational age of 30.9 +/- 0.2 wk and weighed 1.43 +/- 0.03 kg. When tested 3 wk later, their net calcium absorption averaged 58 +/- 1% with an intake of 80 +/- 2 mg Ca.kg body wt-1.d-1. Of the 103 infants, 58 had been fed low-birth-weight formulas supplemented with vitamin D. The remainder received banked human milk, of whom 34 were supplemented with vitamin D and calcium; 11 infants received no supplementation. Calcium absorption in the four subgroups did not differ significantly, with neither vitamin D supplementation nor supplementation with vitamin D and calcium affecting percent absorption significantly. Net calcium absorption was a linear function of intake (40-130 mg Ca.kg body wt-1.d-1) with a zero intercept. Because vitamin D supplementation did not increase net calcium absorption, it is concluded that in preterm low-birth-weight infants calcium absorption proceeds by a nonsaturable route, with the transcellular, vitamin D-regulated mechanism not yet expressed.

Calcium

Lumbar bone mineral content measured by dual energy X-ray absorptiometry in newborns and infants.

Dual energy X-ray absorptiometry (DXA), a non-invasive method for measuring small amounts of mineral, was used to assess the bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine (5 vertebrae) in 57 newborns (on day 1-2) and 22 infants (1-24 months of age). A modified high-resolution program (Hologic) allowed us to assess BMC and BMD with a precision higher than 2.4% and 1.5%, respectively. In newborns, BMC and BMD correlated positively with birth weight, body area, length and gestational age: r = 0.73, 0.71, 0.63 and 0.60, respectively, for BMC; and r = 0.59, 0.58, 0.54 and 0.53, respectively, for BMD. In infants, both BMC and BMD were highly correlated with weight, age, length and body area over two years (r = 0.94 or better in each instance). The data provide normal values for lumbar spine BMC and BMD in newborns (gestational age 31-40) and infants up to two years of age; DXA appears to be an excellent and safe tool for pediatric bone mineral measurements.

Absorptiometry, Photon

Dual energy x-ray absorptiometry measurement of bone mineral content in newborns: validation of the technique.

To evaluate the applicability of dual energy x-ray bone absorptiometry in newborns, precision and accuracy of the method was tested for very small quantities of mineral ranging from less than 0.5 g to about 4 g of hydroxyapatite using a Hologic QDR 1000 instrument. For six femurs excised from preterm stillborns, the mean precision for bone mineral content (BMC) and bone mineral density (BMD) was 1.2 and 0.8%, respectively. Accuracy based on ash weight indicated a mean overestimation of about 7%. In vivo, the precision was assessed by measuring lumbar spine BMC and BMD (L1 to L5) two or three times in 10 newborns (gestational age, 33 to 40 wk). The mean coefficients of variation were 2.40 and 1.55% for BMC and BMD, respectively. Lumbar spine BMC and BMD were also measured once in 30 full-term infants. Values ranged from 1.17 to 3.90 g for BMC and from 0.192 to 0.356 g/cm2 for BMD. The present study shows that dual energy x-ray absorptiometry provides a valuable new tool for the assessment and management of BMC in low birth weight infants and neonates in general.

Absorptiometry, Photon

[Neonatal gastric necrosis].

BACKGROUND: Neonatal necrotizing gastritis is rare. It is usually a complication of acute anoxia or shock and its diagnosis is essentially radiological. CASE REPORTS: Case no. 1: a boy was born at the 36th week of a pregnancy complicated by preeclampsia. Perinatal asphyxia necessitated delivery by cesarean section. He presented with neonatal respiratory distress which was complicated by pneumothorax. On the 5th day of life, the abdomen was distended and the newborn had still not been fed. On the 6th day, X-rays showed pneumatosis of the gastric wall associated with pneumoperitoneum. Surgery showed an area of necrosis on the posterior surface of the stomach with a small perforation, which was stitched. The child was fed 5 days later and was in good condition at the age of 6 months. Case no. 2: a girl was born at the 35th week of a pregnancy complicated by asthma during the second trimester. Perinatal asphyxia and abnormal fetal rhythm led to delivery by cesarean section. At 24 hour of life, she vomited blood and fibroscopy confirmed the presence of blood in the stomach. On the 3rd day, blood vomiting appeared again, associated with abdominal distension. X-rays showed pneumatosis of the gastric wall; fibroscopy showed necrosis of the lower 2/3 of the stomach. Feeding was stopped and the child was given cimetidine. Refeeding was possible when the girl was 10 days old, and she was in good condition at the age of 6 months. CONCLUSION: Neonatal gastric necroses and necrotizing enterocolitis have many similar features. Medical therapy is often effective, but surgery is mandatory when necrotizing gastritis is complicated by perforation.

Female

Dynamic histomorphometric evaluation of human fetal bone formation.

We have evaluated dynamic and static parameters of bone formation in femoral metaphyses collected from two human fetuses at 19 weeks of gestation. Tetracycline was administered to the mother at set intervals (2-5-2 day schedule) before interruption of pregnancy. Labels were distinct and sharply linear, suggesting a well organized calcification front at this early stage of mineralization. Mineral apposition rate (MAR) was fastest (4.1 +/- 0.3 microns/d) in the periosteal (Ps) envelope, and about half that value in the endosteal envelopes (endocortical: 2.5 +/- 0.1, cancellous 2.1 +/- 0.1 microns/d). Because cellular activities may vary throughout the metaphyseal area, sections were arbitrarily separated in 0.75 mm layers starting from the growth plate. Three measured parameters decreased rapidly with increasing distance from the physis: Ps MAR: 4.9 to 2.3 microns/d, trabecular osteoid thickness: 5.9 to 1.2 microns, and cartilage volume (CgV/TV): 5.4% to 1.2%. Others did not vary significantly along the metaphysis. Comparison of several static parameters with those measured in five autopsy specimens from full-term infants showed that bone and cartilage volume, and trabecular thickness increased while osteoid thickness and parameters of resorption decreased in the second half of the gestation period. The study indicates that fetal bone matrix mineralization is already highly organized at mid-gestation, and validates the use of histomorphometry to assess bone maturation during early skeletal development.

Bone Development

[Neonatal mortality and morbidity of low birth weight premature infants (less than or equal to 1500 g)].

Neonatal mortality and morbidity were reported over a 4-yr period from 1986-1989 in premature infants weighing less than 1,500 g, 278 of whom were born in the same obstetrico-neonatal unit. Total mortality was 15%, and was higher in premature infants weighing less than 1,000 g (38%) and lower if the gestational age was greater than 27 wk. Mortality was lower in small for gestational age (SGA) infants than in appropriate for gestational age (AGA) infants (5% vs 19%, P less than 0.001), and lower in inborn babies than in outborn (12% vs 19%, P less than 0.02) but only in neonates weighing less than 1,000 g. Neonatal morbidity was mainly due to hyaline membrane disease and cerebral haemorrhage. The incidence of broncho-pulmonary dysplasia was low (4%). These results indicate that gestational age, birth weight and place of delivery play a role in mortality and morbidity in very low birth weight premature infants.

France

[Infants born to kidney transplant recipients].

Over a period of 24 years, 23 women who had undergone renal transplantation gave birth to 26 children whose gestational ages were above 28 weeks. The average duration of stable kidney function tests before the onset of pregnancy was 34.5 months (6 to 109 months). Immunosuppressive treatment consisted mostly of azathioprine and steroids (20/26), steroids and cyclosporin A (CyA) in one case, and azathioprine, steroids and CyA in 5 cases. Average gestational age at birth was 35.2 weeks (30-40 weeks), average birth weight was 2,330 g (1,160-3,700 g). Caesarean section was performed in 73% of cases. The most frequent neonatal pathological condition was the occurrence of respiratory distress, most often related to prematurity and the mode of delivery. No child presented with any lethal congenital malformation. Children born to mothers who were given CyA did not present with more congenital malformations or renal function impairment.

Adult

Human neonatal hypocalcemia.

Hypocalcemia is commonly observed in the neonatal period and is usually transient from a few days to a few weeks. On only rare occasions is neonatal hypocalcemia permanent and secondary to congenital hypoparathyroidism caused by either isolated absence of parathyroid glands or in association with other malformations. Most cases of neonatal hypocalcemia fall into one of two clinical categories. Namely early neonatal hypocalcemia occurs in 24-48 h of life and it is usually observed in premature infants or infants of diabetic mothers. Late neonatal hypocalcemia is observed at the end of the first week of life. In addition of these two major categories, neonatal hypocalcemia may occur in association with hypomagnesemia.

Female

[Neonatal idiopathic pericardial effusion].

The authors describe a case of hydropericardium occurring in a fullterm neonate presenting with a respiratory distress syndrome due to persistent fetal circulation. The baby was treated by surgery. No etiology could be found to explain this hydropericardium.

Female

[Neonatal surgery: experience of a neonatal obstetrical and surgical unit].

A prospective and retrospective study of the consequences of neonatal surgery started recently in a neonatal intensive care unit. After a prenatal diagnosis of a surgical malformation has been established, the importance of a meeting with parents, neonatologists and surgeons is stressed. The relationships between the family and the neonatal team were good, although sometimes the surgeons seemed to be "forgotten". The infant's pain was usually prevented. Infants were actively managed before surgery and after surgery their rhythms were better respected.

Female

[Surfactants: from biology to therapy].

The authors report on the recent knowledge of biochemistry, synthesis and hormonal regulation of surfactant. Treatment of hyaline membrane disease with exogenous surfactant is discussed.

Animals

[Late neonatal hypocalcemia. Apropos of 33 cases treated with 1 alpha-hydroxycholecalciferol].

Thirty-three observations of late-onset neonatal hypocalcemia were reviewed retrospectively. Their etiological, clinical and biological features were consistent with a transient congenital hypoparathyroidism, associated with a materno-foetal vitamin D deficiency. 1 alpha-hydroxycholecalciferol was used for rapid correction of calcemia and proved to be satisfactorily metabolized after its oral administration.

Calcium

Vitamin D metabolism in preterm infants: effect of a calcium load.

Decrease in serum calcium level leading to hypocalcemia during the first week of life is a frequent finding in premature neonates. Eight premature neonates presenting with such an episode of hypocalcemia in the course of their first 4 days of life were studied. They were fed with a phosphate-enriched human milk and given vitamin D3 (2,100 IU/day per os). We have evaluated the effect of a 24-hour pharmacologic calcium infusion on the circulating levels of calcium, inorganic phosphate, magnesium, 25-hydroxycalciferol (25-OHD), 1 alpha,25-dihydroxycalciferol [1,25(OH)2D] and immunoreactive parathyroid hormone (iPTH). After the infusion, circulating iPTH and Pi levels dropped significantly (p less than 0.025 and p less than 0.005 respectively) whereas serum Ca and 25-OHD (p less than 0.005) increased. Mg and 1,25(OH)2D serum levels remained unchanged. Our data show that an increased calcium supply sustained for 24 h induces an appropriate response in iPTH secretion. Effects on circulating levels of 1,25(OH)2D were variable and probably reflected individual differences in half life of 1,25(OH)2D or in set points in the feedback mechanisms involved in the control of 1,25(OH)2D synthesis.

Calcifediol

Vitamin D metabolism in preterm infants.

Perinatal metabolism of vitamin D was studied in premature babies with the aim of: (1) reporting the relationship between the pregnant mother and her preterm infant and the metabolism of vitamin D during the first weeks of life, and (2) assessing the effect of vitamin D metabolites on phosphorus calcium and magnesium intestinal absorption. There was only a positive correlation between plasma cord calcium and 25-hydroxyvitamin D levels and the mother's plasma levels at birth. During the hypocalcemic episode observed during the first week of life, vitamin D activation did occur, but later on rickets or osteomalacia cannot be due to the low levels of vitamin D metabolites in the preterm receiving an adequate dose of vitamin D (1,000-1,200 IU of D2). Calcitriol, the major metabolite of vitamin D, is acting on the intestine and promotes calcium absorption even in very tiny prematures. The pathogenesis of hypomineralization in the preterm infant is due to the low intake of calcium or phosphorus and/or poor absorption of calcium in the case of vitamin D deficiency.

Calcium

Perinatal serum bone Gla-protein and vitamin D metabolites in preterm and fullterm neonates.

Whether the hypocalcemia often found in premature neonates results from an adaptation to extrauterine life or an expression of imbalanced mineral homeostasis has yet to be established. We compared serum levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D [1,25-(OH)2D], and bone Gla-protein (BGP), a specific marker of bone formation during the first month of life in fullterm and preterm neonates. Measurements were performed in cord blood and on days 1, 5, and 30 of life. In maternal blood, mean serum 1,25-(OH)2D concentrations were higher in the mothers of premature than in those of fullterm neonates, and serum BGP concentrations were lower than those in nonpregnant women. In cord blood mean serum BGP levels were 2-3 times higher than in adults. Serum BGP increased significantly on days 5 and 30 in fullterm infants. In preterm infants, and increase was found only on day 30. Mean serum 25-hydroxyvitamin D and 1,25-(OH)2D concentrations were lower in neonates than in mothers, but not different in fullterm and preterm neonates. In fullterm infants serum 1,25-(OH)2D increased rapidly from birth to day 5 and decreased on day 30. The pattern was similar in preterm infants, but 1,25-(OH)2D was higher than in fullterm infants on day 30. No sustained correlation between serum BGP and 1,25-(OH)2D levels was found. These data support the contention that changes in 1,25-(OH)2D reflect the perinatal equilibration of calcium homeostasis. Serum BGP may be a potential marker of bone growth in premature neonates.

Calcifediol