Successful repair of ectopia cordis using alloplastic materials.

Ectopia cordis is a very rare congenital anomaly associated with a high mortality rate. A successful repair of ectopia cordis with complete absence of sternum was achieved in a two-stage procedure. Initial management consisted of coverage of skin over the malpositioned heart using bilateral pectoral skin flaps. A second more definitive repair was undertaken at age 14 months. Four methyl methacrylate struts were used to reconstruct the anterior chest wall and were then covered with bilateral pectoralis major muscle flaps. At the 2.5-year follow-up there is no evidence of cardiopulmonary compromise and the development of the thorax appears normal. We advise that use of alloplastic materials is a valid option in managing this difficult congenital anomaly.

Magnetic field changes associated with caloric stimulation of the human vestibular organ.

Caloric stimulation of the ear produces a shift of the vestibular resting potential. The current produced by the change in this potential produces a corresponding change in the associated magnetic field. A sensitive magnetic detector (second-derivative gradiometer) was used to detect a large shift in the magnetic field close to the ears of two normal subjects who underwent cold thermic ear stimulation. The shift in the magnetic field tracked the reflex responses in both individuals. This technique could offer a noninvasive direct measure of end-organ function.

Interaction of hemopexin, albumin and liver fatty acid-binding protein with protoporphyrin.

Equilibrium constants for the binding of protoporphyrin to serum albumin and hemopexin and liver cytosolic fatty acid-binding protein of the rat were determined fluorometrically. The experimental equilibrium constant [10(6) M-1 (mean +/- S.D.)] values were 8.4 +/- 1.3, 10.0 +/- 2.4 and 34.0 +/- 3.0 for albumin, hemopexin and liver fatty acid-binding protein, respectively. Statistical analysis showed the equilibrium constant of binding of protoporphyrin to liver fatty acid-binding protein to be significantly (p less than 0.01) higher than that to albumin and hemopexin. The data suggest that in patients with erythropoietic protoporphyria an equilibrium gradient may exist which favors the uptake by hepatocytes of plasma protoporphyrin as a result of its greater affinity for intracellular liver fatty acid-binding protein.

Microcalorimetric investigation of the binding of some chemotherapeutic agents and related molecules to calf thymus DNA.

Batch microcalorimetry was used to estimate directly the standard enthalpies of the binding of small molecules to DNA. These values were compared with those obtained from spectrophotometric binding constants and van't Hoff plots. The close agreement between the independently obtained enthalpies indicates that the appropriate (best) binding model has four phosphates per binding site. Thermodynamic binding constants were obtained from apparent binding constants measured at different ionic strengths. From these and the measured standard enthalpies, standard free energies and standard entropies of binding were calculated. The weak, presumably external, binding alleged to occur at high formal molar concentration ratios of ligand to DNA bases could not be detected by a measurable heat of binding.

Fluvoxamine: metabolic fate in animals.

The metabolic fate in animals of the antidepressant compound fluvoxamine was investigated. The 14C-labeled drug was administered orally to dogs, rats, hamsters, and mice, and excretion in urine and feces was measured. Chromatographic patterns of the urines were developed by high performance liquid chromatography. These patterns were used as guides in the isolation of the metabolites, its initial step consisting of concentration of the radioactivity in the urine pools in a conical precolumn, followed by separation in the same HPLC system as used for the metabolite patterns. Altogether, 32 radioactive substances were isolated from the urine pools of the four animal species. They were all identified by the combined use of proton nuclear magnetic resonance and mass spectrometry, and by information obtained from chromatographic behavior and color reactions. Several of the 32 compounds were identical, leaving a total of 11 different metabolites in the four species. In all the animal species, the main focus of fluvoxamine degradation was its aliphatic methoxyl group. In three species, this resulted in the corresponding carboxylic acid as the main metabolite, but in the mouse the corresponding alcohol, in glucuronidated form, was at least as important. In mouse and hamster, the methyl ester was a minor metabolite. Products of acetylation or oxidative removal of the primary amino group accounted for only minor proportions of the metabolite patterns. While fluvoxamine itself has the (E)-configuration, several metabolites occurred both in the (E)- and the (Z)-form. The parent compound was isolated only from the urine of dogs, it accounted for less than 10% of the urinary radioactivity.

Coarctation of the abdominal aorta with multiple aneurysms. Operative correction.

An 11-year-old asymptomatic girl with hypertension was found to have coarctation of the abdominal aorta with four aneurysms in or adjacent to the hypoplastic segment of aorta. Operative treatment included insertion of a thoracoabdominal aortic bypass graft and resection of the aneurysms. The association of abdominal coarctation and aneurysm formation is reviewed and the rationale for therapy discussed.

Evaluation of intracardiac shunts.

This article will review the qualitative and quantitative methods of radionuclide evaluation of intracardiac shunts. Radionuclide angiocardiography of the cardiopulmonary system has proven adequate, with few exceptions, for qualitative detection of left-to-right and right-to-left intracardiac shunts. Numerous authors have reported on the detection of intracardiac shunts using qualitative methods such as rapid sequential visualization of nuclide angiocardiography using the scintillation camera with Polaroid, 35mm or 70mm film. Recent development of videotape storage systems and computers offers a quantitative technique of permanently recording the nuclide angiocardiogram and thus the capability for replay and analysis of the study. Quantitative analysis of the nuclide angiogram in the form of heart chamber dilution curves or pulmonary dilution curves permits 1) determination of the presence or absence of left-to-right, right-to-left, or bi-directional intracardiac shunts, including shunts which might go undetected using the qualitative techniques, 2) shunt location at the atrial or ventricular level, 3) determination of the functional status of a corrective left-to-right shunt, and 4) shunt quantitation. By quantitative analysis of the isotope dilution curves, it is possible to calculate the size of left-to-right or right-to-left intracardiac shunts (Qp/Qs ratio) to within 10% of the values obtained at cardiac catheterization.

Auditory evoked frequency following responses in man.

A sound-evoked sinusoidal response was recorded from the temporal scalp area in six humans. This evoked signal is similar in its characteristics to (and may correspond with) the "frequency-following response" of Worden and Marsh recorded on the scalp in man by Moushegian and colleagues. The site of origin of the response recorded in these subjects is not known, but it is of interest that the aspect of the scalp, and that the influence of arousal state on response amplitude paralleled the described effects of changes in arousal state on the primary auditory cortical evoked response. This technique may allow for the direct measurement of auditory thresholds across the frequency domain. This is possible because measured responses can be obtained at sound levels of the order of 15 to 20 dB across the frequency range from 300 to 2,500 Hz.

Diagnosis of congenital heart disease in the first two weeks of life.

The differential diagnosis of congenital heart disease which presents cyanosis or respiratory distress, or both, in the first two weeks of life, is difficult. Close correlation of clinical features, electrocardiogram and chest roentgenogram is most helpful. The diagnosis of congenital heart disease should lead to immediate cardiac catheterization, angiocardiography and appropriate therapy.