The association between iron deficiency and outcomes: a secondary analysis of the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial

In the intravenous iron therapy to treat iron deficiency anaemia in patients undergoing major abdominal surgery (PREVENTT) trial, the use of intravenous iron did not reduce the need for blood transfusion or reduce patient complications or length of hospital stay. As part of the trial protocol, serum was collected at randomisation and on the day of surgery. These samples were analysed in a central laboratory for markers of iron deficiency. We performed a secondary analysis to explore the potential interactions between pre-operative markers of iron deficiency and intervention status on the trial outcome measures. Absolute iron deficiency was defined as ferritin <30 μg.l^-1 ; functional iron deficiency as ferritin 30-100 μg.l^-1 or transferrin saturation < 20%; and the remainder as non-iron deficient. Interactions were estimated using generalised linear models that included different subgroup indicators of baseline iron status. Co-primary endpoints were blood transfusion or death and number of blood transfusions, from randomisation to 30 days postoperatively. Secondary endpoints included peri-operative change in haemoglobin, postoperative complications and length of hospital stay. Most patients had iron deficiency (369/452 [82%]) at randomisation; one-third had absolute iron deficiency (144/452 [32%]) and half had functional iron deficiency (225/452 [50%]). The change in pre-operative haemoglobin with intravenous iron compared with placebo was greatest in patients with absolute iron deficiency, mean difference 8.9 g.l^-1 , 95%CI 5.3-12.5; moderate in functional iron deficiency, mean difference 2.8 g.l^-1 , 95%CI -0.1 to 5.7; and with little change seen in those patients who were non-iron deficient. Subgroup analyses did not suggest that intravenous iron compared with placebo reduced the likelihood of death or blood transfusion at 30 days differentially across subgroups according to baseline ferritin (p = 0.33 for interaction), transferrin saturation (p = 0.13) or in combination (p = 0.45), or for the number of blood transfusions (p = 0.06, 0.29, and 0.39, respectively). There was no beneficial effect of the use of intravenous iron compared with placebo, regardless of the metrics to diagnose iron deficiency, on postoperative complications or length of hospital stay.

Cooperating oncogenes converge to regulate cyclin/cdk complexes

The cooperation of oncogenes in the transformation of primary rat Schwann cells is a strikingly synergistic process. We have explored the molecular mechanisms involved. Activation of an inducible Raf kinase results in morphologically transformed cells that are arrested in G1 via the induction of p21(CiP1) and subsequent inhibition of cyclin/cdk activity. In contrast, coexpression of SV40 large T (LT) or a dominant-negative mutant of p53 abolishes p21(CiP1) induction and alleviates the growth arrest. Moreover in this scenario, Raf activation results in an increase in the specific activity of cyclin/cdk complexes with Raf and LT cooperating to superinduce cyclin A/cdk2 activity and stimulate proliferation in the absence of mitogens. Thus, signaling by Raf and its cooperating partners converges at the regulation of cyclin/cdk complexes, with the cellular responses to Raf modulated by p53.

Partial transformation of human thyroid epithelial cells by mutant Ha-ras oncogene

We have previously shown that activation of ras oncogenes by mutation is a frequent early event in human thyroid neoplasia. Using amphotropic retroviral vectors to achieve gene transfer, we demonstrate here that human primary thyroid epithelial cells can be partially transformed by an activated cellular or viral Ha-ras oncogene, in the absence of a cooperating oncogene. The transformation event induced by ras involves temporary rescue from senescence for up to 20 rounds of cell division together with morphological alteration, growth factor independence and anchorage independence. It has therefore been possible to reconstruct in vitro a key early event in the genesis of human epithelial neoplasia.

Absence of activating transmembrane mutations in the c-erbB-2 proto-oncogene in human breast cancer

The rat neu proto-oncogene, which is a putative growth factor receptor closely related to the epidermal growth factor receptor, can be activated in vivo by a single point mutation in the sequence encoding its transmembrane region. The human homologue of neu, c-erbB-2, can be activated in vitro to an oncogenic form by point mutations in the same relative position in the gene. We have sought the presence of such activating mutations in a series of 100 cases of human breast cancer by polymerase chain reaction amplification and sequence-specific oligonucleotide hybridization, and also by a designed restriction fragment length polymorphism strategy in cases with Southern blot evidence of c-erbB-2 amplification. No evidence of activating point mutations in the c-erbB-2 protooncogene was found in any of these cases.