von Willebrand factor-collagen binding activity is increased in newborns and infants

ABSTRACT. von Willebrand factor (vWF) antigen (vWF:Ag) and vWF-collagen binding activity (vWF:CBA) were measured in plasma by parallel quantitative ELISAs in normal newborns and infants ( n =71). The medians for vWF:Ag (IUjml) and vWF:CBA (Ujml), respectively, were 1.46 and 1.91 for 2-7 day-old (n = 43), 1.22 and 1.40 for 2-4 week-old (n = 14), 1.22 and 1.15 for 2-6-month-old (n = 14) infants and 0.98 and 1.08 (n = 36) in normal adults. Elevated levels of vWF:Ag, but particularly vWF:CBA were seen for up to 4 weeks of life reaching adult levels between 2 and 6 months of life. The elevated levels of the vWF parameters indicate that caution should be exercised when interpreting laboratory data and diagnosing von Willebrand disease in newborns and young infants and warrant the use of age-specific reference ranges. The efficient haemostasis observed during early neonatal life may in part be due to the increased ability of vWF to interact with collagen.     

Echocardiogram‐gated multislice spiral CT in functionally univentricular heart following long‐lasting Waterston–Cooley anastomosis

Waterston–Cooley anastomosis may be carried out in patients with tricuspid atresia to provide pulmonary perfusion. It is associated with several complications, including preferential blood flow to the right lung, hypoplasia of the left pulmonary artery, obstruction of the anatomosis or rupture of pulmonary aneurysms. We study a patient with thrombosis in the pulmonary arteries following surgical construction of a Waterston shunt in childhood. Imaging findings and clinical symptoms are discussed with emphasis on echocardiogram‐gated multislice spiral CT.     

Interval between insulin injection and breakfast in diabetes

The relationship between the insulin-breakfast interval, postprandial increase in blood glucose, and glycaemic control was studied in 58 children with diabetes. Patients recorded insulin-breakfast intervals in a home diary over a seven day period, and during a 24 hour period at the weekend provided eight serial capillary dried blood spots for glucose analysis. The highest mean blood glucose value occurred two hours after breakfast and showed a significant correlation with fructosamine concentrations. Weekend insulin-breakfast intervals ranged from 2-30 minutes, with 70% reporting intervals of less than 15 minutes. There was a significant correlation between the weekend insulin-breakfast interval and the after breakfast increase in blood glucose with a mean increment of 0.4 mmol/l in the 30 minute group and 7.2 mmol/l in the 2 minute group. Over the whole study period, children with mean insulin-breakfast intervals of two to 12 minutes had a mean fructosamine concentration of 376 mumol/l compared with 341 mumol/l in those with intervals of 15-35 minutes. This study has shown that the interval between insulin injection and breakfast significantly influences the morning postprandial rise in blood glucose and consequently short term glycaemic control. It is therefore important that patients are encouraged to leave an interval of about 30 minutes between insulin injection and breakfast.     

Colorectal hemangioma: radiologic findings

The authors correlated radiographs with the clinical and histologic data of 12 patients with colorectal hemangioma. All patients presented with rectal bleeding, which was chronic in seven. Phleboliths were also visible in seven cases, which correlated with chronic bleeding in five. On barium studies, three masses were soft and three produced rigid narrowing. The atypical features of rigid luminal narrowing, which might mimic a carcinoma, and hypovascularity correlated with chronic bleeding or visible phleboliths, which suggest the correct diagnosis of colorectal hemangioma.     

Early human thymocyte proliferation is regulated by an externally controlled autocrine transforming growth factor-beta 1 mechanism

Early thymocytes undergo extensive proliferation after their entry into the thymus, but cellular interactions and cytokines regulating this intrathymic step remain to be determined. We analyzed the effects of various T-cell growth factors and cellular interactions on in vitro proliferation of early CD2+CD3/TCR-CD4-CD8- (triple negative [TN]) human thymocytes. Freshly isolated TN cells were then assayed for their growth capacity after incubation with CD2I+III-monoclonal antibody (MoAb), recombinant human interleukin-2 (IL-2), IL-7, and/or IL-4. These cells displayed significant proliferative responses with IL-4, IL- 7, or CD2-MoAb+IL-2. The addition of recombinant transforming growth factor beta (TGF beta) or autologous irradiated CD3+CD8+CD4- cells to TN cell cultures dramatically decreased their growth responses to IL-2 and IL-7, whereas IL-4-induced proliferation was less sensitive to growth inhibition. We thus asked whether the CD8+ cell-derived inhibitory effect was due to TGF beta. The addition of neutralizing anti-TGF beta MoAb completely abolished CD8+ cell-derived inhibition of TN cell growth. Analysis of CD8+ cell-derived supernatants indicated that these cells had low TGF beta 1 production capacity, whereas TN cells secrete significantly high levels of TGF beta 1. Cell fixation studies showed that TN cells were the source of the TGF beta. TGF beta 1 released from TN cells was in the latent form that became the active inhibitory form through interaction of TN cells with CD8+ cells. Together, these data suggest a role for TGF beta 1 as an externally controlled, autocrine inhibitory factor for human early thymocytes, with a regulatory role in thymic T-cell output.