Transesophageal echocardiographic monitoring during coronary artery bypass surgery

To demonstrate serial changes of left ventricular (LV) function during coronary artery bypass grafting surgery, transesophageal echocardiography (TEE) was used in 17 patients. The cross-sectional image of the left ventricle at the level of the papillary muscles was monitored, and was analyzed immediately in the operating room using a computer-assisted cine-memory function. Global LV function was evaluated by measuring LV end-diastolic and end-systolic area and computing the fractional area change (FAC). Segmental wall motion abnormalities (SWMA) were graded according to a scoring system. During the operative procedure before sternal closure, 5 patients showed SWMA with a simultaneous decrease in FAC to under 40%, and 9 patients showed SWMA without FAC depression. Two-thirds of new SWMA improved after myocardial revascularization. All 17 patients showed a change of interventricular septal movement at the end of the operation. FAC improved from a mean value (+/- SD) after intubation of 47.6 +/- 10.7% to a mean value after revascularization of 58.5 +/- 13.0% (p less than 0.05) and to a mean value at the end of the operation of 55.9 +/- 12.2% (p less than 0.05). Thus: 1) global and regional LV function improved immediately after myocardial revascularization with administration of inotropic agents; 2) a significant change of interventricular septal movement occurred after sternal closure; and 3) intraoperative TEE monitoring is a safe, simple, and effective method for evaluating LV global and regional function.

Acute hemodynamic effects of captopril in children with a congestive or restrictive cardiomyopathy

The acute hemodynamic effects of captopril were evaluated at cardiac catheterization in 16 children (age, 0.3-18 years) with cardiomyopathy. Twelve children had congestive cardiomyopathy, whereas four had restrictive cardiomyopathy. Hemodynamic measurements were obtained 30 and 60 minutes after the oral administration of captopril (0.5 mg/kg). Blood pressures were measured in the aorta, pulmonary artery, right atrium, and pulmonary capillary wedge position; cardiac outputs were measured by the thermodilution technique. Hemodynamic data could not be obtained after the administration of captopril in one child with congestive cardiomyopathy because of an immediate, severe hypotensive response. In 11 of 12 children with congestive cardiomyopathy, cardiac index increased by 22%, from 2.3 to 2.8 l/min/m2 (p less than 0.05), and stroke volume increased by 22%, from 23 to 28 ml/m2 (p less than 0.05). Systemic vascular resistance decreased from 32 to 21 units.m2 (p less than 0.01), but the mean aortic pressure did not change significantly. In contrast, four children with restrictive cardiomyopathy had no change in cardiac output after captopril, but there was a trend toward significant arterial hypotension (mean aortic pressure decreased from 78 to 59 mm Hg). Thus, captopril acutely reduced systemic vascular resistance and increased both cardiac output and stroke volume in children with congestive cardiomyopathy. In children with restrictive cardiomyopathy, however, captopril did not affect cardiac output, but it did decrease aortic pressure. These data indicate that captopril may benefit children with a congestive cardiomyopathy but that captopril probably should not be used in children with restrictive disease.

Formulation, nutritive value and sensory evaluation of a new weaning food based on sweet corn (Nutrimaiz) dehydrated pulp

The objective of the present work was to develop a formulation for complementary infant and child feeding employing linear programing as a mathematical model for optimization. High lysine/high tryptophan sweet corn pulp in the dehydrated form was used as the main ingredient. The restrictions imposed on the model were nutrient requirements, adequate protein/energy ratio and minimum cost. The formula derived by the computer (FC) matched the amino acid requirements, the protein/energy ratio (NDPCal%) and was rated high in laboratory tests in terms of sensory qualities. The cost determined for this formula was competitive in relation to commercial products used for the same purpose. Formula A, which contained 5% more sweet corn pulp and 10% less whole powdered milk, did not differ in nutritional, sensorial and functional properties from the formula FC and was chosen for the field acceptability trial because of its lower cost. Formula A had protein efficiency ratio and Biological Value similar to casein for the rat but protein digestibility and net protein utilization were statistically lower (p less than 0.05) for formula A than for casein. Acceptability tested on children who were 8-18 months of age ranged from 80-90%, average value 87%.

Longitudinal results after first-stage palliation for hypoplastic left heart syndrome

To evaluate the results of palliative surgery for hypoplastic left heart syndrome, we reviewed the records of 57 infants who underwent first-stage reconstruction at our institution between July 1983 and April 1989. Of the 57 infants, 12 (21%) are long-term survivors and 45 (79%) have died. Thirty-one infants died within the first 30 days after surgery. Twenty-six of the 31 early deaths occurred within the first 24 hours after surgery. Causes of early mortality were low cardiac output (23), sepsis (two), sudden death (two), pulmonary vein atresia (three), and cardiac transplant (one). Late death occurred in 14 infants due to sepsis (three), sudden death (four), and death at reoperation (seven - three after Fontan procedure, three after shunt replacement, and one after transplant). Of the 31 patients who survived more than 24 hours, the complications noted by echocardiography and confirmed by catheterization when reoperation was indicated were significant arch obstruction (13%), branch pulmonary artery stenosis (23%), small atrial septal defect (16%), inadequate shunt (26%), neoaortic regurgitation (13%), tricuspid regurgitation (13%), ventricular dysfunction (29%), thrombus (6%), and superior vena cava obstruction (3%). Of the 31 patients who survived more than 24 hours, 16 additional palliative surgical procedures were performed in eight patients. These procedures included arch reconstruction (four), additional shunt (four), Glenn shunt (three), atrial septectomy (two), coarctation balloon angioplasty (two), and pulmonary artery reconstruction and reshunting (one). Of the 12 long-term survivors, four have had a successful Fontan procedure, one has had a transplant, and seven are awaiting a second-stage procedure. Thus, 69% of all deaths occurred within the first 30 days of surgery, and 58% of all deaths occurred within the first 24 hours due to cardiovascular collapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaccine protection of rhesus macaques against simian immunodeficiency virus infection

Rhesus macaques (Macaca mulatta) immunized with an inactivated whole SIVmac vaccine and muramyl dipeptide (MDP), incomplete Freund's adjuvant (IFA), or aqueous suspension were challenged intravenously with 0.1 TCID50 of cell-free SIVmac. Whereas virus was readily recovered from the peripheral blood lymphocytes of 10 of 10 nonvaccinated controls following this challenge dose, virus was not recovered from the three animals that received the vaccine with MDP nor from one of two animals that received the vaccine with IFA and one of three animals that received the aqueous vaccine. The animals that were protected against challenge were those that had detectable SIV antibody response to the envelop, both the outer glycoprotein (gp120) and the truncated transmembrane glycoprotein (gp31). Protected monkeys tended to have higher titers of syncytial inhibition antibody prior to challenge. An anamnestic response after challenge was observed only in the vaccinated monkeys that became infected. Vaccinated animals that became challenge-infected tended to live longer than infected controls. These results confirm those at two other primate centers and indicate that killed whole SIV vaccines can protect against low challenge doses of SIV and prevent early death in those monkeys that do become infected. The mechanism of this protection remains undetermined. This finding adds optimism to the possibility of an eventual AIDS vaccine.

Widespread expression of BDNF but not NT3 by target areas of basal forebrain cholinergic neurons

Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF.

Shone's anomaly: operative results and late outcome

Shone's anomaly, a congenital cardiac malformation, consists of multiple levels of left heart obstruction including supravalvar mitral ring, parachute mitral valve, subaortic stenosis, and coarctation. The prognosis for patients with Shone's anomaly is poor. To assess operative results and late outcome, we reviewed the records of 30 consecutive patients seen with Shone's anomaly at our institution between 1966 and 1989. Anatomical diagnoses in these patients were supravalvar mitral ring (22 patients), mitral valve abnormalities including parachute mitral valve, fused chordae, or single papillary muscle (26 patients), subaortic gradients (26 patients), and coarctation (29 patients). Nineteen patients had all four lesions. Other common defects were bicuspid aortic valve (19 patients) and ventricular septal defect (20). Two patients were treated medically. The other 28 patients required 84 operative procedures with 18 patients undergoing more than one procedure. Operations included coarctation repair (28 patients), mitral valve repair or replacement (11), ventricular septal defect closure (8), subaortic resection (8), and complex left ventricular outflow tract reconstruction or bypass (4). Age at first operation ranged from 7 days to 7 years (median age, 3 months). There were no operative deaths at the first operation. However, mortality rose to 24% (4/17) after the second operation. All operative deaths were secondary to severe mitral valve disease. The survivors have been followed from 1 to 16 years (mean follow-up, 6 +/- 1 years). There were no late or sudden deaths. Morbidity has included stroke (1), gastrointestinal bleeding (2), permanent heart block (1), and persistent congestive heart failure (6).(ABSTRACT TRUNCATED AT 250 WORDS)

Genomic walking and sequencing by oligo-cassette mediated polymerase chain reaction

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Primary structure and biological activity of a novel human neurotrophic factor

During development, each tissue receives and maintains a number of specific neuronal projections that are adequate to sustain its function. The mechanism by which this intricate process occurs is not well understood, but it has been proposed that diffusible neurotrophic factors derived from the target tissue may be involved. Here we describe the identification of a novel human protein that is important for the growth, differentiation, and survival of primary sympathetic and placode-derived sensory neurons. This polypeptide, designated neuronotrophin-3, has a broad tissue distribution and is structurally related to both nerve growth factor and brain-derived neurotrophic factor. Its unique range of trophic and differentiation-inducing activities suggests that it is likely to play a wide role in defining the fate and function of nerve cells during development.

Trans-activation of HIV-1 LTR-directed gene expression by tat requires protein kinase C

Human immunodeficiency virus (HIV) spends a significant part of the viral life cycle as a latent provirus integrated into the host genome. Activation of latent HIV-1 requires mitogenic stimulation of the cell, which increases basal viral transcription, and the HIV-1 tat protein. As tat itself dramatically increases HIV-1 gene expression, it too is presumably regulated in the latent state, and may also be activated by mitogenic stimulation. We show here that depletion of protein kinase C (PKC), which is essential to the stimulation of T cells by several mitogens, dramatically reduces HIV-1 transactivation without affecting synthesis of tat protein. Transactivation in PKC-depleted cells can be restored by transfection with a PKC expression vector. The requirement for PKC in trans-activation does not involve the PMA-responsive enhancer elements responsible for the effect of mitogens on basal transcription. Our results indicate that PKC regulates the process of HIV-1 transactivation, suggesting a key role for the mitogenic induction of trans-activation in the transition of HIV from latency to productive growth.

[Transesophageal echocardiography during coronary bypass surgery]

Transesophageal two-dimensional echocardiography (TEE) was evaluated in 14 patients who underwent coronary bypass surgery. The TEE transducer was positioned to view the left ventricular short axis at the level of the papillary muscle. Global left ventricular function was assessed by measuring left ventricular end-diastolic and end-systolic area and computing the fractional area change (FAC). Regional left ventricular function was analyzed after dividing the short axis view of the left ventricle into four anatomic segments. The mean FAC was 48% after intubation, 48% after skin incision, 47% after sternotomy, and 51% after pericardiotomy. The mean FAC increased significantly to 55% 0 to 30 minutes after cardiopulmonary bypass, and was 53% at the end of the operation. In 5 patients, FAC decreased and regional wall motion abnormalities appeared around sternotomy. These abnormalities was considered due to transient myocardial ischemia. In 7 patients, a paradoxical motion of the ventricular septum occurred at closing of the sternum. TEE was performed without complication and found to be a good method for assessing global and regional left ventricular function.

Reconstruction of the oral commissure after an electrical burn

A burn of the oral commissure is one of the most common types of electrical injury in children. To minimize postoperative wound contracture in late reconstructive surgery, a functional reconstruction that combines excision of the burn scar with lateral advancement of the orbicularis oris muscle, re-creation of the modiolus labii, and reestablishment of vermilion continuity has been developed. Functional restoration of the labial musculature to the preinjury position with re-creation of the modiolus labii and reestablishment of vermilion continuity appears to significantly decrease the amount of postoperative wound contracture (p less than 0.025).

Automated sequencing of fluorescently labelled DNA by chemical degradation

A new general method for sequencing fluorescently labelled DNA by chemical degradation has been developed. It is based on the observation that fluorescein attached via a mercaptopropyl or aminopropyl linker arm to the 5'-phosphate of an oligonucleotide is stable during the reactions commonly used in chemical cleavage procedures. DNA to be degraded is first enzymatically synthesized in vitro by annealing and extending a fluorescently labelled primer thereby introducing the fluorescent label at the 5'-end of the fragment. The newly synthesized fluorescently labelled DNA is then chemically degraded using: (a) a set of four different cleavage reactions; or (b) only one reaction comprising methylation of G-residues followed by a partial cleavage with piperidine in the presence of sodium chloride. The fluorescent degradation products are loaded on either four lanes or one lane of the gel, respectively, and the emitted fluorescence detected online during electrophoresis. In the 'four reactions/four lanes' method 200-350 bp (base pairs) can be read from the labelled end. The 'one reaction/one lane' method, in which the nucleotide sequence is determined by measuring different signal intensities following the rule G greater than A greater than C greater than T, currently yields around 100-200 bp of sequence per sample.

Thrombogenicity of total parenteral nutrition solutions: II. Effect on induction of endothelial cell procoagulant activity

Thrombosis is a common sequela of total parenteral nutrition. We have recently demonstrated in vitro that hypertonic total parenteral nutrition solutions are potent inducers of a tissue factor monocyte procoagulant activity, the initiating cofactor of the extrinsic clotting cascade. We have further studied, in vitro, the effects of the component solutions of total parenteral nutrition on the induction and modulation of endothelial cell procoagulant activity. Cultured porcine aortic endothelial cells were incubated with (a) 200 microliters of dextrose solution (5%, 10%, 20%, 25%, and 50%), (b) 200 microliters of amino acid solution [full strength (N), one-fourth strength, and one-half strength], and (c) 200 microliters of 10% lipid emulsion. Cocultures of lipid emulsion and 20% dextrose, lipid emulsion and full-strength 10% amino acid solution (N-amino acid), and lipid emulsion and bacterial lipopolysaccharide also were studied. Cells were incubated for intervals of 3-108 h, washed and frozen, harvested, and assayed for endothelial cell procoagulant activity. Units of endothelial cell procoagulant activity were derived from a standard thromboplastin curve. Our results show that amino acid and hypertonic dextrose total parenteral nutrition solutions are able to strongly induce endothelial cell procoagulant activity expression in vitro. In contrast, lipid emulsion significantly inhibited the induction of endothelial cell procoagulant activity by 20% dextrose, N-amino acid, and lipopolysaccharide. These results provide further evidence for the role of the cellular pathways of coagulation in total parenteral nutrition-induced thrombosis. Furthermore, the inhibitory properties of lipid emulsion may be of practical advantage in reducing total parenteral nut induced thrombosis.

Usefulness of the Doppler mean gradient in evaluation of children with aortic valve stenosis and comparison to gradient at catheterization

To assess the usefulness of the Doppler mean gradient as a noninvasive indicator of the need for intervention, 33 children (ages 3 months to 20 years) with valvular aortic stenosis (AS) underwent a 2-dimensional and Doppler echocardiographic examination a median of 1 day before cardiac catheterization. The clinical decision for intervention was based on finding a catheterization peak-to-peak pressure gradient of greater than 75 mm Hg or from 50 to 75 mm Hg in the presence of symptoms or an abnormal exercise treadmill test result. Of the 33 patients, 23 required intervention. The decision for intervention was compared to the Doppler mean gradient, and the Doppler peak and mean gradients were compared to the catheterization peak-to-peak gradient. All 12 patients with a Doppler mean gradient greater than 27 mm Hg had intervention and had a catheterization peak-to-peak gradient of greater than or equal to 75 mm Hg. All 3 patients with a Doppler mean gradient less than 17 mm Hg had no intervention and had a peak-to-peak gradient less than 50 mm Hg. The remaining 18 patients with Doppler mean gradients between 17 and 27 mm Hg comprised an intermediate group in whom the Doppler mean gradient alone did not predict the need for intervention. From a chi-square table, a Doppler mean gradient greater than 27 mm Hg predicted the need for intervention with 100% specificity (no false positives) and 52% sensitivity (11 false negatives).(ABSTRACT TRUNCATED AT 250 WORDS)

Polymerase chain reaction for detection of the pMP6d-9/MspI RFLP, a marker closely linked to the cystic fibrosis mutation

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Aortic aneurysm after patch aortoplasty repair of coarctation: a prospective analysis of prevalence, screening tests and risks

Twenty-nine children were evaluated prospectively for the presence of an aortic aneurysm at the repair site 1 to 19 years after patch aortoplasty repair of coarctation of the aorta. In each child, noninvasive evaluation included a chest X-ray film, computed tomography of the chest and two-dimensional echocardiography. The presence and size of an aortic aneurysm were determined quantitatively by measuring the ratio of the diameter of the thoracic aorta at the repair site to the diameter of the aorta at the diaphragm (aortic ratio). An aortic ratio of greater than or equal to 1.5 was judged abnormal and was shown to be significantly greater than the aortic ratio of a normal control group. An aortogram was obtained in each child if any noninvasive screening test was found to be abnormal. As assessed by the aortogram, the prevalence of aortic aneurysm was 24% in this patient group. The sensitivity of echocardiography and chest computed tomography for detecting an aneurysm was 71% and 66%, and the specificity 76% and 85%, respectively. The chest X-ray film was 100% sensitive and 68% specific in determining the presence of an aneurysm. Although the data are not statistically significant, they suggest that children undergoing patch aortoplasty as the primary procedure (rather than a reoperation after earlier resection), and children in whom a Dacron patch is utilized may be at increased risk for aneurysm formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler evaluation of homograft valved conduits in children

To assess the flow characteristics of homograft valved conduits in the immediate postoperative period, 69 children with 71 homograft conduits underwent 2-dimensional and Doppler echocardiographic examination at 1 to 40 days (mean 8) after surgery. Of the 71 conduits studied, 19 were aortic and 52 were pulmonary homograft valved conduits. Two aortic homograft valved conduits were inserted in the aortic position, whereas all remaining homografts were placed in the pulmonary position. On the immediate postoperative echocardiogram, 25 (35%) of the conduit valves had no regurgitation and 44 (62%) had 1+ (mild) regurgitation. Two pulmonary valved conduits (3%) in the pulmonary position had 2+ (moderate) regurgitation and right ventricular dimensions greater than 95% for body surface area. The peak velocity across the homograft valve was normal (less than 1.3 m/s) in 58 valves (82%). In the remaining 13 valves, peak velocity ranged from 1.4 to 2.6 m/s. No homograft valve had a peak velocity greater than 2.6 m/s in the immediate postoperative period. To assess the fate of homograft valved conduits in the intermediate-term follow-up period, 38 children with 38 conduits had a repeat echocardiogram at 6 to 25 months (mean 15 +/- 6) after surgery. Of the 38 conduits examined, 10 (26%) had no regurgitation, 25 (66%) had 1+ regurgitation and 3 (8%) had 2+ regurgitation. Progression of the amount of regurgitation occurred in 11 (29%) patients. At the follow-up examination, peak velocity was less than or equal to 1.4 m/s across 34 conduit valves, between 1.4 and 2.6 m/s across 3 valves and greater than 2.6 m/s across 1 valve.(ABSTRACT TRUNCATED AT 250 WORDS)