Biomedical subjects
Publications and source records attributed to H Alton.
This article is a pictorial review of the major abnormalities of the pulmonary vessels in children. Vascular, including lymphatic malformations have been covered in previous issues of this journal and so will not be described in detail. Many pulmonary vascular abnormalities are associated with complex intracardiac disorders. This article, however, focuses on extra cardiac abnormalities, particularly those causing pulmonary parenchymal problems.
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We report a 15-year-old girl who presented with renal failure requiring dialysis and a diagnosis of p-ANCA-associated vasculitis. She subsequently developed cerebral vasculitis during treatment with oral cyclophosphamide and prednisolone. Treatment with intravenous cyclophosphamide and plasma exchange produced a complete recovery.
BACKGROUND: Our aims were to evaluate left ventricular uptake of radionuclide in patients with Mustard's or Senning's procedure, comparing them with patients who had undergone banding of the pulmonary trunk and conversion to the arterial switch. METHODS: Technetium perfusion scans were performed on 27 patients (25 male), aged from 10 to 28 years with a mean of 17.8 years and a standard deviation of 5.8 years, who had undergone Mustard's or Senning's procedure for correction of complete transposition. Of the 27 patients, six had been accepted for staged conversion to an arterial switch. At the time of the study, two of the six patients had undergone completion to the switch and four had undergone banding of the pulmonary trunk with two then proceeding to the arterial switch. Cardiac catheterisation to measure left ventricular pressure was performed in all six patients and scores for left ventricular uptake of isotope were compared with echocardiographic index of the thickness of the left ventricular posterior wall and measurements of left ventricular pressure. RESULTS: Uptake of isotope by the left ventricle was generally poor, but was higher in patients following banding and conversion to the arterial switch, as well as in two patients with native obstruction of the left ventricular outflow tract, and one other who subsequently was found to have pulmonary venous obstruction. There was a positive correlation between the thickness of the left posterior wall in diastole and left ventricular uptake of isotope (r = 0.74, p < 0.05). There also a positive correlation between left ventricular pressure and uptake of the isotope (r = 0.68, p < 0.05). CONCLUSIONS: Uptake of radionuclide by the left ventricle after Mustard's or Senning's procedure for complete transposition appears to reflect ventricular pressure and myocardial mass. A prospective study would be required to determine the predictive ability of such scans regarding the ultimate outcome of conversion to arterial switch, but our initial findings suggest that the technique provides an additional non-invasive method of monitoring left ventricular response to pulmonary arterial banding.
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A 2.5 year old girl with metachromatic leukodystrophy presented with acute respiratory distress and was initially wrongly diagnosed with pneumothorax. Barium meal showed bowel loops in the left hemithorax, which prompted surgical intervention; spontaneous rupture of the diaphragm was diagnosed at surgery.
We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity. The ultrasound scan appearance was graded and correlated with laboratory parameters. It remains unclear as to the aetiology of the ultrasound findings and whether they are a consequence of treatment or a hitherto unrecognised feature of the disease.
Hepatic artery thrombosis is a major cause of morbidity and mortality following liver transplantation. We assessed the value of prospective duplex Doppler ultrasound in detecting hepatic artery thrombosis. One hundred consecutive transplants in 90 patients were studied. Duplex Doppler detected all 10 proven cases of hepatic artery thrombosis. No case of hepatic artery thrombosis was found with a normal duplex study. All arteriograms performed following an abnormal ultrasound demonstrated hepatic arterial occlusion or anastomotic stenosis or a segment of irregular arterial narrowing. We conclude that duplex Doppler is a practical and sensitive method of selecting patients with a presumptive diagnosis of hepatic artery thrombosis for further investigation by angiography.
Airway aspiration of foreign materials in children and adults is probably more common than has been supposed. This study investigated the possibility of such aspiration in children while under general anesthesia for dental extractions. A radiopaque fluid was used to coat the oral tissues and showed that a significant number of children did aspirate material into the trachea, bronchi, and occasionally even lung tissue. The notion that safety may be improved by operating with the patient in the supine position was not confirmed. While careful placement of an oropharyngeal pack may prevent solid material from entering the trachea and bronchi, it should be realized that fluids such as blood, saliva, and pus could still contaminate the airway.
Prior to 1970, most patients with tricuspid atresia (TA) and reduced pulmonary blood flow were palliated by means of a systemic to pulmonary artery shunt (SPAS). In Birmingham between 1967 and 1988, 19 patients with TA (aged 16 days to 23 years, mean 3.8 years) have undergone side-to-side cavopulmonary anastomosis (CPA) with preservation of pulmonary artery continuity. One had undergone a previous right Blalock-Taussig shunt and in 1 patient with left and right SVCs, bilateral CPAs were performed. Nine patients were less than 1 year old at the time of operation. There were no operative deaths. One late death occurred due to pneumonia. Immediate clinical improvement occurred in all cases. Six symptomatic patients subsequently required further surgery (mean interval between operations 8.9 years, range 4.6-14.2 years). The remaining 12 patients have recently been reviewed. Mean follow-up was 9.5 years (range 5 weeks to 21 years). Exercise tolerance remains good (9 in NY-HA Class 1 or 2) and resting transcutaneous oxygen saturations are higher (mean 85%, range 70%-89%) compared with preoperative values (P less than 0.01). In small children, CPA avoids the complications of SPAS and, in some patients, may itself achieve adequate long-term definitive palliation.
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Noradrenaline synthesis and metabolism of dopamine was evaluated in three patients with familial dysautonomia and compared with that of six normal subjects. Each patient and subject was infused with 104.8 muCi of dopamine-2-(14)C dissolved in 1000 ml of physiological saline. The urine was collected during the infusion period and at intervals thereafter. Using a specially designed flow monitor system, the various biosynthetic and metabolic products of dopamine were separated, identified, and their radioactivity measured. The results indicate that in familial dysautonomia the synthesis of noradrenaline is significantly decreased; this is reflected by a decrease in recovery of radioactive noradrenaline as well as various metabolic products of noradrenaline, i.e. 3-methoxy-4-hydroxymandelic acid (MOMA), normetadrenaline, and normetadrenaline conjugate. Concomitant with this decrease in noradrenaline synthesis, there was a shift towards dopamine metabolism as reflected by an increase in the recovery of primary and secondary dopamine metabolites; 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxy-4-hydroxyphenylacetic acid (HVA), 3-methoxytyrosine, and respective conjugates, etc. Whereas all dysautonomic patients showed the same general metabolic pattern as was expected, they varied in degree.
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After severe thermal injury, the adrenal medulla and the sympathetic nerves can be partially or totally depleted of their adrenaline (epinephrine) and noradrenaline (norepinephrine). The purpose of this paper is to elucidate the rate at which dopamine-2-(14)C, a precursor of noradrenaline, is synthesized into noradrenaline and noradrenaline metabolic products, thereby giving some indication as to dopamine's utilization, turnover, and possible use in treating such noradrenaline-adrenaline depletions. Three burned subjects, 3 wk postburn, were infused with 104.6 muc (872 mug) of dopamine-2-(14)C for 4 hr. Urine was collected at various hourly intervals for the 1st day, and thereafter for 4 days, assayed, and compared with the metabolism of dopamine in normal subjects. Methods for separating, identifying, and counting radioactivity of the various metabolic products of dopamine are described. Normally 87.6 +/-3.1% of the total radioactivity is recovered within 24 hr after an infusion of dopamine-2-(14)C, but in the three severely burned patients, this value was increased to 93.1, 97.3, and 97.5% in 24 hr. There was a marked decrease in the percentage of radioactivity recovered as noradrenaline in all collection periods, and in contrast to normal subjects, no radioactive noradrenaline was recovered after 24 hr. Concomitantly, there was an increase in radioactivity recovered as metabolic products of noradrenaline, reflecting a compensatory shift toward noradrenaline synthesis and utilization at the expense of the dopamine metabolic products. The results indicate that in the burned patients the infused dopamine-2-(14)C was rapidly synthesized into noradrenaline and then rapidly released and metabolized. From these results it seems evident that dopamine would be a useful adjunct in the treatment of sympathico-adrenal medullary depletion in burns.
Three patients with idiopathic parkinsonism and six normal subjects were infused over a 4 hr period with 104.6 muc of dopamine-2-(14)C (3,4-dihydroxyphenylethylamine, 3-hydroxytyramine),(1) the immediate precursor in the synthesis of the sympathetic neurohormone, noradrenaline (norepinephrine). Urine was collected during the infusion period, 0-2 hr, 2-4 hr, 4-8 hr, 8-24 hr, and thereafter for 4 additional days. Using a technique herein described, the various metabolic and biosynthetic products of dopamine, including noradrenaline and its metabolic products, were separated, identified, and their radioactivity measured. The metabolic pattern of dopamine in the normal subject was compared to that of the three parkinsonism patients. The results indicate that in idiopathic parkinsonism there is a decrease in the recovery of free radioactive noradrenaline in the urine following an infusion of dopamine-2-(14)C and a slight shift toward dopamine metabolism. The latter is reflected by an increase in the following metabolites of dopamine: 3,4-dihydroxyphenylacetic acid and the conjugates of 3-methoxy-4-hydroxyphenylacetic acid, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethanol and dopamine.
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