The Global Rating Scale complements the AGREE II in advancing the quality of practice guidelines

ObjectiveTo explore the role of a four-item Global Rating Scale (GRS) that could be used in place of the Appraisal of Guidelines, Research and Evaluation II (AGREE II).Study Design and SettingA mixed four-factor design was used (User Type, Evaluation Type, Clinical Topic, Guideline). Participants were asked to read and evaluate a guideline using both the AGREE II draft and GRS or GRS only and to complete a series of questions regarding overall guideline quality, adoption, utility, and acceptability.ResultsOne GRS item varied as a function of User Type. Each item was a significant predictor of participants' outcome measures. All items were rated as useful by stakeholders. The GRS rating scores, outcome measures, and usefulness scores did not vary between the two Evaluation Type conditions. Correlations between the GRS and the outcome measures were stronger compared with those between the AGREE II draft and these measures.ConclusionAlthough the GRS is less sensitive than the AGREE II in detecting differences in guideline quality as a function of User Type, its items did predict important outcome measures related to guideline adoption. The GRS may play a role in guideline evaluation, although further study is warranted.     

Modification of P-selectin glycoprotein ligand-1 with a natural killer cell-restricted sulfated lactosamine creates an alternate ligand for L-selectin

Natural killer (NK) cells are components of the innate immune system that can recognize and kill virally infected cells, tumor cells, and allogeneic cells without prior sensitization. NK cells also elaborate cytokines (e.g., interferon-gamma and tumor necrosis factor-alpha) and chemokines (e.g., macrophage inflammatory protein-1alpha) that promote the acquisition of antigen-specific immunity. NK cell differentiation is accompanied by the cell surface expression of a mucin-like glycoprotein bearing an NK cell-restricted keratan sulfate-related lactosamine carbohydrate, the PEN5 epitope. Here, we report that PEN5 is a post-translational modification of P-selectin glycoprotein ligand-1 (PSGL-1). The PEN5 epitope creates on PSGL-1 a unique binding site for L-selectin, which is independent of PSGL-1 tyrosine sulfation. On the surface of NK cells, the expression of PEN5 is coordinated with the disappearance of L-selectin and the up-regulation of Killer cell Ig-like Receptors (KIR). These results indicate that NK cell differentiation is accompanied by the acquisition of a unique carbohydrate, PEN5, that can serve as part of a combination code to deliver KIR(+) NK cells to specific tissues.     

Refractory anaemia and mitochondrial cytopathy in childhood

SUMMARY. We report two cases of childhood myelodysplasia (MDS) related to a mitochondrial (mt) cytopathy that illustrate the difficulty in recognizing such disorders in patients with solely haematological signs. Both patients have refractory anaemia with ring sideroblasts and vacuolization of haemopoietic precursors. These cytological features are similar to those observed in Pearson's disease, recently identified as a mitochondrial disease, and are strongly suggestive of a mitochondrial enzyme defect. The diagnosis of mitochondrial cytopathy was established on Southern blotting of mt DNA, showing a mt DNA deletion, or on the impairment of the respiratory chain enzyme activities. The absence of cytogenic abnormalities, and the polyclonal pattern of peripheral neutrophil and lymphocyte fractions, suggest that, in mt cytopathies, MDS cannot be considered as a truly malignant disorder.     

Second autologous transplantation after failure of a first autologous transplant in 18 patients with non-Hodgkin's lymphoma

High-dose chemotherapy and autologous marrow or peripheral stem cell support offers the best chance of cure in some subgroups of patients with non-Hodgkin's lymphoma (NHL). Less is known about the role of a second course of myeloablative chemotherapy in patients who relapse after a first autologous transplant. The aim of this retrospective study was to evaluate the disease outcome, morbidity and mortality associated with second autologous transplantation in patients with NHL. Between 1985 and 2001, 225 patients who had received autologous transplantation for NHL in two institutions in Lyon relapsed. Of these 225 patients 18 underwent a second autologous transplantation. The median age at second transplant was 41 years. There were six indolent lymphomas and 12 aggressive lymphomas. The median follow-up from the second transplant was 42 months. The OS rate at 2 and 5 years were 58 and 27%, respectively. The PFS rate at 2 and 5 years was 36%. Five patients are alive without disease 20 to 100 months after the second transplant. Seven patients died of disease recurrence. Four (22%) toxic deaths occurred: one of pulmonary fibrosis, one of fungal infection and cardiac failure and two of acute leukaemia. A minority of patients with NHL recurrence after a first transplant can be cured by a second course of myeloablative chemotherapy at the cost however of high-risk toxic death.     

Phenothiazines induce PP2A-mediated apoptosis in T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive cancer that is frequently associated with activating mutations in NOTCH1 and dysregulation of MYC. Here, we performed 2 complementary screens to identify FDA-approved drugs and drug-like small molecules with activity against T-ALL. We developed a zebrafish system to screen small molecules for toxic activity toward MYC-overexpressing thymocytes and used a human T-ALL cell line to screen for small molecules that synergize with Notch inhibitors. We identified the antipsychotic drug perphenazine in both screens due to its ability to induce apoptosis in fish, mouse, and human T-ALL cells. Using ligand-affinity chromatography coupled with mass spectrometry, we identified protein phosphatase 2A (PP2A) as a perphenazine target. T-ALL cell lines treated with perphenazine exhibited rapid dephosphorylation of multiple PP2A substrates and subsequent apoptosis. Moreover, shRNA knockdown of specific PP2A subunits attenuated perphenazine activity, indicating that PP2A mediates the drug’s antileukemic activity. Finally, human T-ALLs treated with perphenazine exhibited suppressed cell growth and dephosphorylation of PP2A targets in vitro and in vivo. Our findings provide a mechanistic explanation for the recurring identification of phenothiazines as a class of drugs with anticancer effects. Furthermore, these data suggest that pharmacologic PP2A activation in T-ALL and other cancers driven by hyperphosphorylated PP2A substrates has therapeutic potential.