Bioconversion of glucose and fructose to sorbitol and gluconic acid by untreated cells of Zymomonas mobilis.

The bioconversion of glucose and fructose to gluconic acid and sorbitol, respectively, by the enzymes glucose-fructose oxidoreductase (GFOR) and glucono-delta-lactonase (GL), contained in untreated cells of Zymomonas mobilis ATCC 29191, was investigated in batch runs with glucose plus fructose concentrations (S0) varying from 100 to 750 g l-1 in equimolar ratio. When S0 was increased to 650 g l-1, the yields were improved, reaching a maximum of 91% for both products, with productivities of 1.6 and 1.

Improved results with selective management in pulmonary atresia with intact ventricular septum.

Objective: Late outcome of neonatal pulmonary atresia with intact ventricular septum remains poor in most reported series. We have followed a selective approach toward either single ventricle repair versus complete or partial biventricular repair based on the presence of right ventricle-dependent coronary circulation and growth of the right ventricle.

Methods: A retrospective chart review was conducted of 47 patients who underwent surgery between January 1991 and September 1998.

Echocardiographic assessment of interrupted aortic arch.

Background: In patients with interrupted aortic arch echocardiography provides detailed information about the anatomy of the aortic arch and the associated cardiac anomalies. Only a few reports have evaluated the reliability of this non-invasive diagnostic procedure by correlation with angiographic and surgical findings.

Methods: From 1988 through 1993, 45 infants with interrupted arch underwent surgical repair (mean age 13.

Repair of tetralogy of Fallot in neonates and young infants.

Background: The timing of repair of tetralogy of Fallot (TOF) remains controversial. Advantages to early complete repair include removal of right ventricular outflow tract obstruction, alleviation of systemic hypoxia, and avoidance of palliation with an arteriopulmonary shunt.

Methods And Results: This is a retrospective review of 99 children with TOF pulmonary stenosis (TOF/PS) or TOF pulmonary atresia (TOF/PA) who were <90 days of age undergoing early complete repair.

Developmental outcome after surgical versus interventional closure of secundum atrial septal defect in children.

Background: The assessment of the impact of cardiopulmonary bypass (CPB) on developmental outcomes in children who undergo open heart surgery is hampered by the absence of a suitable comparison group. The development of interventional catheterization techniques for the repair of certain types of congenital heart lesions provides the opportunity to study children who have not been exposed to CPB.

Methods And Results: We performed standardized neuropsychological testing on children after closure of a secundum atrial septal defect through the use of surgery (n=26) or a transcatheter device (n=19).

Forty-one years of surgical experience with congenital supravalvular aortic stenosis.

Objective: Several techniques for symmetric reconstruction of the aortic root in congenital supravalvular aortic stenosis have been developed, but it remains unclear whether these prove superior to patch enlargement of the noncoronary sinus alone. We reviewed our experience with surgical treatment of supravalvular aortic stenosis and investigated the impact of the surgical technique on long-term results.

Methods And Results: Seventy-five patients underwent operations to treat congenital supravalvular aortic stenosis at our institution between 1957 and 1998.

Valved homograft conduit repair of the right heart in early infancy.

Background: Valved homograft conduit repair in neonates and young infants creates a physiologically normal biventricular circulation, and unlike shunts, avoids surgery on the branch pulmonary.

Methods: Retrospective chart review was used for 84 patients operated on between 1990 and 1995 (mean age 26+/-28 days, mean weight 3.3+/-0.

The effect of hematocrit on cerebral blood flow velocity in neonates and infants undergoing deep hypothermic cardiopulmonary bypass.

Unlabelled: Varying degrees of hemodilution are used during deep hypothermic cardiopulmonary bypass. However, the optimal hematocrit (Hct) level to ensure adequate oxygen delivery without impairing microcirculatory flow is not known. In this prospective, randomized study, cerebral blood flow velocity in the middle cerebral artery was measured using transcranial Doppler sonography in 35 neonates and infants undergoing surgery with deep hypothermic cardiopulmonary bypass.

Developmental and neurological status of children at 4 years of age after heart surgery with hypothermic circulatory arrest or low-flow cardiopulmonary bypass.

Background: It is not known whether developmental and neurological outcomes in the preschool period differ depending on whether the predominant vital organ support strategy used in infant heart surgery was total circulatory arrest (CA) or low-flow cardiopulmonary bypass.

Methods And Results: Infants with D-transposition of the great arteries who underwent an arterial-switch operation were randomly assigned to a support method consisting predominantly of CA or low-flow cardiopulmonary bypass. Developmental and neurological status were evaluated blindly at 4 years of age in 158 of 163 eligible children (97%).

A novel sialyl Lewis X analog attenuates cerebral injury after deep hypothermic circulatory arrest.

Background: The initial step in the inflammatory process, which can be initiated by cardiopulmonary bypass and by ischemia/reperfusion, is mediated by interactions between selectins on endothelial cells and on neutrophils. We studied the effects of selectin blockade using a novel Sialyl Lewis X analog (CY-1503) on recovery after deep hypothermic circulatory arrest in a piglet model.

Methods: Twelve Yorkshire piglets were subjected to cardiopulmonary bypass, 30 minutes of cooling, 100 minutes of circulatory arrest at 15 degrees C, and 40 minutes of rewarming.

Oxygenation strategy and neurologic damage after deep hypothermic circulatory arrest. II. hypoxic versus free radical injury.

Objectives: Laboratory studies suggest that myocardial reperfusion injury is exacerbated by free radicals when pure oxygen is used during cardiopulmonary bypass. In phase I of this study we demonstrated that normoxic perfusion during cardiopulmonary bypass does not increase the risk of microembolic brain injury so long as a membrane oxygenator with an arterial filter is used. In phase II of this study we studied the hypothesis that normoxic perfusion increases the risk of hypoxic brain injury after deep hypothermia with circulatory arrest.

Oxygenation strategy and neurologic damage after deep hypothermic circulatory arrest. I. Gaseous microemboli.

Objectives: Recent studies suggest that myocardial reperfusion injury is exacerbated by free radicals when pure oxygen is used during cardiopulmonary bypass. Partial replacement of the oxygenator gas mixture with nitrogen, however, such as has already been adopted clinically in many centers, could increase the risk of gaseous nitrogen microembolus formation and therefore of brain damage because of the low solubility of nitrogen, particularly under conditions of hypothermia.

Methods: Ten 7- to 10-kg piglets were cooled for 30 minutes to 15 degrees C on cardiopulmonary bypass and then rewarmed for 40 minutes to 37 degrees C.

Preoperative management of pulmonary venous hypertension in hypoplastic left heart syndrome with restrictive atrial septal defect.

A severely restrictive atrial septal defect (ASD) in neonates with hypoplastic left heart syndrome (HLHS) results in pulmonary venous hypertension, pulmonary edema, and intractable hypoxia. Between January 1983 and June 1998, 21 of 355 neonates presenting with HLHS (5.9%) underwent cardiac catheterization at median age 1 day (range 0 to 25), for creation or enlargement of a restrictive or absent interatrial communication.

Management of distal tracheal stenosis.

Objective: To evaluate the treatment, perioperative management, and outcome of infants who underwent repair of congenital tracheal stenosis. We hypothesized that early resection and tracheoplasty with early weaning of ventilatory support results in less mucosal injury, and thus better outcome.

Design: Retrospective study from 1986 to 1996.

Left ventricular assist device improves survival in children with left ventricular dysfunction after repair of anomalous origin of the left coronary artery from the pulmonary artery.

Background: Repair of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in infants carries a high operative risk, particularly in infants with myocardial infarction and poor left ventricular function. The marked recovery of left ventricular function reported late after repair, however, suggests that an aggressive approach to repair should be undertaken.

Methods: Of 31 children undergoing primary repair of ALCAPA at our institution from 1987 to 1996, 26 were infants (6 weeks to 9 months old).

Mechanical circulatory support in children with cardiac disease.

Objective: To review the experience from a single center that uses both extracorporeal membrane oxygenation and ventricular assist devices for children with cardiac disease requiring mechanical circulatory support.

Methods: A retrospective chart review was performed for all pediatric patients with cardiac disease who required support with extracorporeal membrane oxygenation or ventricular assist devices. Statistical analysis of the impact of multiple clinical parameters on survival was performed.

One step partial purification of beta-D-galactosidase from Kluyveromyces marxianus CDB 002 using STREAMLINE-DEAE.

The intracellular enzyme beta-D-galactosidase provides interesting applications in the dairy industry, which are able to solve problems related to product processing, or can alleviate lactose intolerance in some populations. In order to obtain a technical enzyme, yeast cells of Kluyveromyces marxianus CDB 002 were disrupted by high pressure homogenization and an innovative chromatographic technique was tested for the recovery of beta-D-galactosidase. A STREAMLINE 25 column, containing 65 ml STREAMLINE-DEAE was equilibrated with 50 mM potassium phosphate buffer pH 7.

Myocardial protection for neonates and infants.

This report reviews developmental differences between mature and immature myocardium. These differences, which are structural, biochemical, and functional, probably explain the differences which are observed between mature and immature myocardium with respect to resistance to ischemia. Although there are some clinical reports and also laboratory reports suggesting that immature myocardium ist more susceptible to ischemic injury than mature myocardium, it is our impression at Children's Hospital, Boston, that immature myocardium is in fact more resistant to ischemia.

Postischemic hyperthermia exacerbates neurologic injury after deep hypothermic circulatory arrest.

Background: Aggressive surface warming is a common practice in the pediatric intensive care unit. However, recent rodent data emphasize the protective effect of mild (2 degrees - 3 degrees C) hypothermia after cerebral ischemia. This study evaluates different temperature regulation strategies after deep hypothermic circulatory arrest with a survival piglet model.

Near-infrared spectrophotometry of the brain in cardiovascular surgery.

Neuropsychological and neurological deficits are still major causes of mortality and morbidity after cardiac operations and are thought to be caused by embolism and cerebral hypoxia. Near-infrared spectrophotometry (NIRS) is a promising method for non-invasive monitoring of cerebral oxygenation and hemodynamics. Different devices provide information on changes of oxygenated (HbO2) and deoxygenated hemoglobin (Hb), oxidized cytochrome aa3 (CytOx) or regional oxygen saturation (rSO2).

Use of rapid-deployment extracorporeal membrane oxygenation for the resuscitation of pediatric patients with heart disease after cardiac arrest.

Introduction: We have recently used extracorporeal membrane oxygenation as a means of rapidly resuscitating pediatric patients with heart disease after cardiopulmonary arrest, in whom conventional resuscitation measures have failed.

Methods: We developed a fully portable extracorporeal membrane oxygenation circuit that is maintained vacuum and carbon dioxide-primed at all times. When needed, the circuit is crystalloid-primed and can be ready for use within 15 minutes.