Biopterin derivatives in normal and phenylketonuric patients after oral loads of L-phenylalanine, L-tyrosine, and L-tryptophan

Plasma biopterin derivatives studied in 10 normal and 21 phenylketonuric children showed a significantly high concentration in the latter group. Biopterin derivatives correlated with plasma phenylalanine concentration, but in normal adults given an oral phenylalanine load the rate of increase with phenylalanine differed from that in phenylketonuric patients. A patient with hyperphenylalaninaemia, not due to phenylketonuria, had an abnormal biopterin derivatives response to phenylalanine distinct from that of patients with classical phenylketonuria. This may be a useful investigation to differentiate some variants of phenylketonuria.     

Current practice in dietary management of diabetic children. A transatlantic comparison

Dietary therapy practice in 18 British clinics for diabetic children is reviewed, and contrasted with Canadian and American practice. Values for dietary composition expressed as energy are presented for small groups of British and Canadian children. Fat is often the principal energy source in British diabetic children; protein intake is much higher in the Canadian. It is suggested that British practice might be improved by the adoption of a simple uniform exchange system. Reported differences in growth characteristics may reflect differences in protein intake.     

Central line sepsis in a child due to a previously unidentified mycobacterium

A rapidly growing mycobacterium similar to strains in the present Mycobacterium fortuitum complex (M. fortuitum, M. peregrinum, and M. fortuitum third biovariant complex [sorbitol positive and sorbitol negative]) was isolated from a surgically placed central venous catheter tip and three cultures of blood from a 2-year-old child diagnosed with metastatic hepatoblastoma. The organism's unique phenotypic profile and ribotype patterns differed from those of the type and reference strains of the M. fortuitum complex and indicate that this organism may represent a new pathogenic taxon.     

Plasminogen activation transforms the morphology of quiescent 3T3 cell monolayers and initiates growth.

Plasminogen activator of cell origin converts the plasma protein plasminogen to the proteolytic enzyme plasmin. Recently, high levels of activator have been observed to be particularly associated with tumours and transformed cells, and a functional relationship between plasminogen activation and malignancy has been proposed. In this paper we have attempted to induce transformation-like morphology and growth in a population of confluent quiescent cells in tissue culture, by inducing plasminogen activation. Untransformed 3T3 cells grown to confluence in plasminogen-free medium were subjected to plasminogen activation by the addition of urokinase and plasminogen or plasminogen-containing acid-treated serum, or plasmin. Under these conditions, the previously well ordered monolayers became disrupted, with multilayering, and discontinuities in the cell sheet, and the cells simultaneously grew to significantly higher densities. Removal of the plasmin-containing medium supplements effected some restoration of normal morphology. Thus, lhen plasmin was present 3T3 cells did not become transformed, but expresses transformation-like features. Well ordered monolayer morphology and quiescence in 3T3 cells at confluence are therefore dependent upon the absence of plasminogen activation.     

Decreased splenic enhancement on CT in traumatized hypotensive patients

Three patients with transient episodes of hypotension following blunt abdominal trauma incurred in motor vehicle accidents were examined by computed tomography within 6 hours of injury. The examinations were done using a contrast material injection technique that ordinarily leads to greater splenic than hepatic attenuation. None of the patients had splenic injury evident on autopsy, surgery, or clinical follow-up study (one case each), nor did they have other characteristic features of splenic infarction. However, in each case the spleen was less enhanced than the liver, leading to an erroneous impression in one patient that the splenic artery had been disrupted. Physiologic studies have shown that splenic perfusion decreases with sympathetic stimulation; this may have been the cause of the diminished enhancement. Decreased splenic enhancement should be interpreted cautiously in traumatized hypotensive patients.     

Arthrographic study of painful total hip arthroplasty: refined criteria

The criteria for a diagnosis of loosening or infection of hip arthroplasties on arthrographic study were further refined by a retrospective review of 178 arthrograms representing 170 patients. The 97 arthroplasties that were surgically evaluated form the basis of this report. With the refined criteria, subtraction arthrography had a sensitivity of 96% and specificity of 92% for demonstrating loosening of the femoral component and a sensitivity of 97% and a specificity of 68% for demonstrating loosening of the acetabular component. Pseudocapsule size and the presence of bursae were important factors influencing arthrographic interpretation. Arthrographic findings of pseudocapsule irregularity and the presence of nonbursal cavities were suggestive of infection but were not sensitive or specific. Laboratory evaluation of aspirated material was a more reliable predictor of infection, although its sensitivity was only 71%.     

Breast mass detection by US: a phantom study

Phantoms were used to compare imaging of various masses in the glandular region for two types of breasts. In one type, normal glandular tissue contains no fat clumps; in the other type, randomly distributed spherical fat clumps exist. The size distribution and number of fat clumps per unit volume in the phantoms represented those found in actual normal glandular tissue. For a 5-cm path length between the scanning window of the phantom and the centers of the masses, the presence of the fat clumps caused distortions and deviations of the beam, resulting in image distortion. This degradation was reduced when successive slabs of the material containing the fat clumps were removed. Image degradation appeared to be less severe when a 2.25 (rather than a 3.5) MHz transducer was used. The results show that the thickness of tissue containing fat clumps between the scanning transducer and a mass plays a role in the detectability of masses and diagnostic usefulness of the image of a breast. This suggests that imaging of the breast in the compressed configuration should be performed regardless of whether the freely suspended breast is imaged. Also, transducers of lower nominal frequency may have an important role in breast imaging.     

Pitfall in MR imaging of lymphadenopathy after lymphangiography

In two patients examined with magnetic resonance (MR) imaging after lymphangiography, opacified pelvic lymph nodes could not be distinguished from subcutaneous or retroperitoneal fat because of the short T1 and long T2 relaxation times of lymphangiographic contrast media. Opacified nodes removed from one patient had relaxation times similar to those of fat. Thus, assessment of lymphadenopathy with MR imaging should be performed before lymphangiography to obviate this potential pitfall.