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Biomedical subjects

E Anday

Publications and source records attributed to E Anday.

13 recordsLinked to original sources
PubMed2000

Preliminary evaluation of dual wavelength phased array imaging on neonatal brain function.

Imaging of human tissue using noninvasive techniques has been of great interest in biomedical fields. Optical imaging has attracted a lot of attention because of its portability and economy. The possibility that a highly portable, fast, safe, and affordable imaging system which could obtain interpretable images of brain function for pre- and full-term neonates in a few seconds, has been explored in this article. We have used a sensitive optical topography system, termed phased array, in which a pair of equal-amplitude and antiphase light sources are applied to generate a sharp amplitude null and phase transition plane. This two-wavelength (750 and 830 nm), frequency encoded (50 and 52 MHz) phased array imaging system can indicate the blood concentration and oxygenation changes in blood model studies and during parietal brain activation in neonates. Significant functional responses, particularly to parietal stimulation in normal and pathological states of neonatal brain, have been revealed in our study. The preliminary clinical results are presented in this article.

Blood Flow Velocity↗
PubMed1995

One-year follow-up evaluation of 260 premature infants with respiratory distress syndrome and birth weights of 700 to 1350 grams randomized to two rescue doses of synthetic surfactant or air placebo. American Exosurf Neonatal Study Group I.

A multicenter, randomized, double-blind, placebo-controlled trial of synthetic surfactant therapy for premature infants with respiratory distress syndrome (RDS) and birth weights of 700 to 1350 gm demonstrated a reduction in severity of RDS, morbidity, and neonatal and 1-year mortality. Of the 419 infants who were entered in the study, 80% of the surviving infants in both the air placebo group (122) and the synthetic surfactant group (138) returned for the follow-up evaluation at 1-year adjusted age. The only significant difference observed at follow-up was a reduction in the incidence of mild cerebral palsy in the synthetic surfactant group (air placebo group, 8 of 122 (7%); synthetic surfactant group, 3 of 138 (2%); relative risk 0.306; 95% confidence interval 0.094, 0.999). No differences were observed between the air placebo and synthetic surfactant treatment groups with respect to health status of the infants, including the incidence of retinopathy of prematurity and neurodevelopmental delays. The difference in the overall incidence of impairment among the 1-year survivors in the air placebo group (43 of 122 (35%)) and in the synthetic surfactant group (40 of 138 (29%)) was not statistically significant. The results of this 1-year follow-up study show that rescue treatment with synthetic surfactant in infants weighing 700 to 1300 gm is not associated with adverse developmental consequences despite the improvement in survival.

Air↗
PubMed1994

Non-immune hydrops fetalis associated with impaired fetal movement: a case report and review.

Non-immune hydrops fetalis (NIHF) is due to many different causes. Fetal hypomobility has been alluded to as a possible cause. We present a preterm fetus with NIHF secondary to fetal hypomobility. Fetal movements were undetected after the 20th week of gestation. The infant was born 8 weeks later and was edematous, had pleural effusions, and no spontaneous movements. He died on day four of life. Diffuse massive central nervous system (CNS) destruction found on post-mortem examination was thought to be the origin of the hypomobility. As all other causes of NIHF were eliminated, we propose that the NIHF in this infant was due to the hypomobility. This case then gives support to the assertion that fetal hypomobility is another cause of NIHF. The cause of the CNS catastrophy remains unelucidated.

Brain↗
PubMed1994

Effect of acute cocaine injection on the extracellular level of dopamine, blood flow, and oxygen pressure in brain of newborn piglets.

The present study examined the effects of acute cocaine administration on oxygen pressure in the vasculature of the cortex as well as on blood flow and extracellular levels of dopamine in the striatum of newborn piglets. The oxygen-dependent quenching of phosphorescence was used to continuously monitor oxygen pressure in the vasculature of the cortex. Following acute cocaine injection (1.5 mg/kg iv) the cortical oxygen pressure rapidly decreased from 36.3 +/- 1.2 to 32.9 +/- 1.4 Torr and remained at the lower level during the 120 min of postinjection period during which measurements were made. Blood flow in striatum, as determined by laser Doppler, was decreased by 8-10% at 5 min after injection of cocaine. This decrease in blood flow was statistically significant up to 40 min postinjection. Extracellular dopamine, measured using in vivo microdialysis, showed a large increase after cocaine injection. The dopamine level increased from 14 +/- 7 to 88 +/- 21 pmol/ml by 15 min after drug administration, then decreased to 45 +/- 11 pmol/ml and remained stable for the 120 min post-injection period. The mechanism(s) by which the increase in the extracellular level of dopamine occurred may include a direct effect of cocaine on the dopamine transporter and/or an indirect effect due to the decrease in cerebral oxygenation and blood flow. The increase in extracellular dopamine can be responsible for several alterations in neuronal metabolism with potentially deleterious effects on neuronal function.

Animals↗
PubMed1993

Cocaine and its metabolites constrict cerebral arterioles in newborn pigs.

We examined the effect of cocaine and several of its metabolites on cerebral arterioles in newborn pigs and evaluated the sympathomimetic properties of each of the compounds as a vasoactive mechanism. After piglets were equipped with closed cranial windows, compounds were suffused over the brain surface and pial arteriolar diameter (base line, approximately 100 microns) was recorded. Cocaine, cocaethylene, norcocaine, ecogonine, benzoylecgonine and ecgonine methylester each caused a dose-dependent (10(-8) M to 10(-4) M) decrease in pial arteriolar diameter: maximum percent reductions in diameter induced by each compound (10(-4) M) were, respectively, 12 +/- 1, 12 +/- 2, 11 +/- 1, 7 +/- 1, 7 +/- 2 and 5 +/- 1. In analyzing the dose-response curves, cocaethylene was the most potent vasoconstrictor, followed by cocaine, norcocaine and then ecogonine, benzoylecgonine and ecgonine methylester. Cerebral vasoconstriction induced by topically applied norepinephrine was enhanced by cocaine, norcocaine and cocaethylene, but not by the other three metabolites. Topical application of phentolamine failed to block vasoconstriction elicited by cocaine or its metabolites, although it did block vasoconstriction elicited by norepinephrine. These observations indicate that cocaine and its metabolites constrict the immature cerebrovasculature by a non-sympathomimetic mechanism.

Animals↗
PubMed1992

Controlled trial of a single dose of synthetic surfactant at birth in premature infants weighing 500 to 699 grams. The American Exosurf Neonatal Study Group I.

In a multicenter, double-blind, placebo-controlled trial conducted at 23 hospitals in the United States, a single prophylactic 5 ml/kg dose of a synthetic surfactant (Exosurf Neonatal) or air placebo was administered shortly after birth to 215 infants with birth weights of 500 to 699 gm. Despite stratification at entry by birth weight and gender, by chance female infants predominated in the air placebo group and male infants predominated in the surfactant group. Among infants receiving synthetic surfactant, improvements in oxygen requirements were significant at 2 hours after birth (p = 0.014) and persisted for 3 days (p = 0.001); improvements in the alveolar-arterial partial pressure of oxygen gradient were significant at 6 hours after birth (p = 0.01) and persisted for 3 days (p = 0.008). Improvements in mean airway pressure were not significant at 2 or at 6 hours after birth (p = 0.622 and 0.083, respectively), but became significant thereafter and persisted for 3 days (p = 0.002). Pneumothorax was reduced by slightly more than half (25 vs 11; p = 0.014); death from respiratory distress syndrome (RDS) was also reduced (26 vs 15; p = 0.046). Overall neonatal mortality, however, was not significantly reduced (58 vs 46; p = 0.102). Other complications of RDS and prematurity were not altered, except that pulmonary hemorrhage occurred significantly more frequently in infants receiving synthetic surfactant (2 vs 12; p = 0.006). These findings indicate that a single prophylactic dose of synthetic surfactant in infants weighing 500 to 699 gm at birth improves lung function, incidence of air leak, and death from RDS but not overall mortality. The only safety problem identified was an increase in pulmonary hemorrhage.

Bronchopulmonary Dysplasia↗
PubMed1988

An epidemic of adenovirus 7a infection in a neonatal nursery: course, morbidity, and management.

An epidemic of adenovirus 7a in our neonatal intensive care nursery and intermediate care nursery in July and August 1987 caused the death of two patients. Significant symptomatic infection possibly due to the virus occurred in nine patients, ten staff, and three parents, of whom three patients, three staff, and one parent were positive by culture. As a direct consequence of the outbreak, 58 staff days of work were lost; the intensive care nursery had to be closed to admissions for 19 days and the intermediate care nursery for 14 days. Seventeen newborns were transferred to other hospitals and four mothers were sent elsewhere for delivery. Control measures, which included cohorting of patients, use of gloves, gowns and goggles, and exclusion of symptomatic staff from the unit, appeared effective. Rapid immunofluorescence testing of virological specimens was of little use in monitoring the outbreak, largely because of poor specimen quality. This outbreak further underlines the ease of transmission and high morbidity of neonatal adenovirus infection.

Adenoviridae Infections↗
PubMed1987

Campylobacter jejuni enteritis in a premature neonate.

We have described the first case of Campylobacter jejuni enteritis in a premature neonate, whose clinical course was characterized by a self-limited bloody diarrhea accompanied by metabolic acidosis and poor weight gain. The importance of this organism in causing preterm labor in mothers and enteritis in premature neonates awaits systematic study.

Campylobacter Infections↗
PubMed1987

Brain oxidative phosphorylation following alteration in head position in preterm and term neonates.

An alteration in head position, which effects cerebral blood flow, may increase the risk for intraventricular hemorrhage in the critically ill infant. The purpose of this study was to evaluate in vivo cerebral oxidative metabolism as an index of tissue oxygen delivery reflecting brain blood flow, in healthy preterm and term infants following a change in head position. Cerebral phosphoenergetics using 31 phosphorus nuclear magnetic resonance spectroscopy were measured in 10 preterm and eight term infants following three different head positions: neutral, prone, and supine. All infants were clinically stable at the time of study. The phosphocreatine to inorganic phosphate ratio, an indicator of bioenergetic reserve, was determined. The mean +/- SD for phosphocreatine to inorganic phosphate ratio in the neutral position in preterm and term infants was 1.08 +/- 0.15 and 1.12 +/- 0.21, respectively, and did not change significantly following head turning. These data suggest that any alteration in cerebral blood flow as a result of a change in head position in the healthy neonate may be compensated by physiological and biochemical regulations so that no changes in brain oxidative phosphorylation are measurable.

Brain↗
PubMed1987

Metatropic dwarfism. Uncoupling of endochondral and perichondral growth.

Metatropic dwarfism is a rare heritable skeletal dysplasia that is thought to result from a defect in endochondral ossification. Histological studies have been few and have yielded inconsistent findings. In addition, no investigator has commented on the structure and function of the perichondral portion of the growth plate in patients who have metatropic dysplasia. To further characterize this disturbance, histological studies were carried out on autopsy specimens from the proximal part of the femur and the iliac crest of a patient who had this disorder. The major findings were: the absence of formation of normal primary spongiosa in the metaphysis; the presence of a thin seal of bone at the chondro-osseous junction, with abnormal metaphyseal vascular invasion and arrest of endochondral growth; and normal-appearing perichondral ring structures with persistence of circumferential growth. These findings suggest an uncoupling of endochondral and perichondral growth and offer an explanation for the dumbbell-shaped morphological structure of the osseous metaphysis that is seen in patients who have metatropic dysplasia. Other observations included prominence of the cartilaginous canals and vascular channels in the reserve zone; clumping of chondrocytes with enhanced staining of the pericellular matrix in the proliferative zone; a decreased ratio of cells to matrix in the hypertrophic zone, with intracellular metachromatic granules and incomplete evolution of chondrocytes; complete absence of an alcian-blue-positive zone of provisional calcification; and, finally, islands of dysplastic chondrocytes in the metaphysis. These abnormalities suggest that metatropic dysplasia is not simply a disorder of endochondral ossification. There appear to be associated defects in the longitudinal proliferation and maturation of chondrocytes and in the production of normal matrix.

Achondroplasia↗
PubMed1986

Staphylococcus epidermidis-associated enterocolitis.

Nineteen infants (mean +/- SD gestational age 30 +/- 2 weeks, birth weight 1.28 +/- 0.53 kg) with Staphylococcus epidermidis bacteremia were found on retrospective chart review to have had signs and symptoms of acute enterocolitis. This S. epidermidis-associated enterocolitis constituted 37% of the 51 cases of enterocolitis and 23% of the 81 cases of S. epidermidis sepsis during the study period. S. epidermidis-associated enterocolitis was relatively mild compared with other forms of enterocolitis. Although abdominal radiographs showed markedly abnormal bowel gas patterns with distended bowel loops and bowel wall edema, only one infant had pneumatosis intestinalis and none had portal venous or free intraperitoneal gas. Only three infants had neutropenia, and five had thrombocytopenia. None of these infants required surgical intervention. Although bloody stools often persisted for weeks, none of the neonates had prolonged feeding intolerance or development of a stricture. We conclude that S. epidermidis infection is commonly associated with a mild form of enterocolitis in the neonate and that this association should be considered when selecting antibiotics for therapy.

Enterocolitis↗