Effect of exercise on portal vein blood flow in man

PURPOSE

Doppler pulsed flow and electronic scanning allow for instantaneous measurement of portal vein flow. This method was used to monitor alterations in splanchnic blood flow during exercise.

METHODS

Measurements of portal vein blood flow were performed in eight healthy males at rest and at 10-min intervals during cycle ergometry at 70% of maximal aerobic capacity. Subjects stopped cycling briefly (approximately 30 s) and stopped breathing while measurements were made. Flow was calculated from values obtained for velocity of red blood cell passage and cross-sectional area of the vessel.

RESULTS

Cross-sectional area decreased during exercise, resulting in a significant decrease in flow over time (P = 0.0001 by ANOVA). The flow within the portal vein had decreased by 80% after 60 min of exercise (absolute flow, 0.63 +/- 0.13 L x min(-1) at rest and 0.13 +/- 0.04 L x min(-1) at 60 min).

CONCLUSION

Electronic Doppler flow measurement of portal vein flow is a viable, noninvasive technique that can be used to measure splanchnic blood flow. Values obtained as a result of intensive exercise are in line with earlier results obtained with other techniques.

Coexistence of an adrenocortical carcinoma with an abdominal ganglioneuroma in a child

We report a 3-year, 5-month-old boy with an adrenocortical carcinoma. These tumours are rare and highly malignant in childhood. In most cases they are functional, secreting adrenocortical hormones. In this case there was a misleading coexistence with a second abdominal neoplasm, which was a ganglioneuroma; this is a rare benign tumour arising from the sympathetic nervous system. The imaging investigations and their findings are discussed and correlated with pathology.

Syntenin, a PDZ protein that binds syndecan cytoplasmic domains

The syndecans are transmembrane proteoglycans that place structurally heterogeneous heparan sulfate chains at the cell surface and a highly conserved polypeptide in the cytoplasm. Their versatile heparan sulfate moieties support various processes of molecular recognition, signaling, and trafficking. Here we report the identification of a protein that binds to the cytoplasmic domains of the syndecans in yeast two-hybrid screens, surface plasmon resonance experiments, and ligand-overlay assays. This protein, syntenin, contains a tandem repeat of PDZ domains that reacts with the FYA C-terminal amino acid sequence of the syndecans. Recombinant enhanced green fluorescent protein (eGFP)-syntenin fusion proteins decorate the plasmamembrane and intracellular vesicles, where they colocalize and cosegregate with syndecans. Cells that overexpress eGFP-syntenin show numerous cell surface extensions, suggesting effects of syntenin on cytoskeleton-membrane organization. We propose that syntenin may function as an adaptor that couples syndecans to cytoskeletal proteins or cytosolic downstream signal-effectors.

Pulmonary and mediastinal lesions in children with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is an uncommon group of disorders affecting mainly children and young adults. In children, pulmonary involvement occurs mostly in the disseminated forms; isolated pulmonary lesions are unusual. A retrospective study was undertaken on a group of 42 children diagnosed with LCH over a 19-year period. Eight children (19 %) had radiological evidence of pulmonary involvement. The lung lesions were either present at the time of diagnosis or, when appearing during the course of the disease, always coinciding with exacerbation or recurrence of the disease in other sites. Lung involvement did not appear to be an unfavourable prognostic factor. However, the toxic effects of treatment on the lungs might lead to important pulmonary sequelae.

Idiopathic infantile arterial calcification: a surviving patient with renal artery stenosis

Idiopathic infantile arterial calcification (IIAC) is a rare hereditary, fatal disease. Death occurs usually within the first 28 months of life. IIAC is characterized by calcifications along the internal elastic membrane and proliferation of the intimal layer of muscular arteries. Specific therapy consists of administration of diphosphonates, but its effectiveness has been a matter of controversy. We report a case treated with diphosphonates which has had an unusual outcome.

Magnetic resonance imaging in tracheal compression by the innominate artery

Tracheal compression by the innominate artery is frequently suspected in infants with noisy breathing and no obvious aortic arch anomalies or pulmonary artery sling. However the diagnosis is difficult to confirm. The findings after using magnetic resonance imaging in two infants with tracheal compression syndrome are presented.

[Technetium 99m labeled dimercaptosuccinic acid (99m Tc-DMSA) scintigraphy in the diagnosis and follow-up of urinary infections in children]

BACKGROUND

The site of a urinary tract infection (UTI) is located by clinical findings plus imaging techniques. Renal imaging with technetium 99mTc-dimercaptosuccinic acid (99mTc-DMSA) has shown promise but its efficacy for detecting acute pyelonephritis is still debated as is its ability to differentiate between acute, potentially curable disease and scarring, definitive changes.

PATIENTS AND METHODS

The files of all the 166 patients that underwent one or two (32 patients) 99mTc-DMSA imaging sessions for UTI in 1989 and 1990 in our department were analysed. The results of this technique were compared with the clinical and laboratory data and with those of other imaging techniques (ultrasonography and retrograde voiding cystourethrogram). The patients (92 girls and 74 boys, mean age: 5 years, range 15 days-17 years) were assigned to one of 3 categories: 1) acute pyelonephritis (27 patients), 2) low UTI (60 patients) and 3) uncertain UTI (79 patients), on the basis of the clinical and laboratory data.

RESULTS

The first 99mTc-DMSA imaging was normal in 110 children; changes were unilateral in 45 and bilateral in 11 children. Images suggesting either acute or chronic changes were observed respectively in 19 and 48 children. 4 of the 7 acute changes were normalized on the second radioisotope scanning while 2 became worse; 19 of the 23 chronic changes were unchanged at the second scanning. Radioisotope scanning changes were seen in 81% of the patients classified as acute pyelonephritis and in only 27% of those with lower UTI. Reflux was detected in 56% of abnormal kidneys and in 36% of normal kidneys. The results of radioisotope scanning and ultrasound scan findings were not correlated in 24 patients (19 only abnormal radioisotope imaging, 5 only abnormal ultrasound scan).

CONCLUSIONS

DMSA scans are useful for investigating and following UTI. They help to distinguish acute pyelonephritis and lower UTI. It is a reliable method of detecting structural abnormalities and identifying children at risk of progressive renal damage.