Molecular detection of t(8;21)/AML1-ETO in AML M1/M2: correlation with cytogenetics,morphology and immunophenotype

The t(8;21) identifies a subgroup of acute myeloid leukaemia (AML) with a relatively good prognosis which may merit different treatment. It is associated predominantly, but not exclusively, with AML M2, and corresponds to rearrangements involving the AML1 and ETO genes. AML1-ETO positive, t(8;21) negative cases are well recognized but their incidence is unknown. In order to determine optimal prospective AML1-ETO RT-PCR screening strategies, we analysed 64 unselected AML M1 and M2 cases and correlated the results with other biological parameters. Molecular screening increased the overall detection rate from 8% to 14%. AML1-ETO was found in 3% (1/32) of AML M1 and 25% (8/32) of M2, including three patients without a classic t(8;21) but with chromosome 8 abnormalities. It was more common in younger patients. Correlation with morphology enabled development of a scoring system which detected all nine AML1-ETO-positive cases with a false positive rate of 7% (4/55). Although certain AML1-ETO-positive cases demonstrated characteristic immunological features (CD19 and CD34 expression, CD33 negativity), each of these markers was insufficiently specific to permit prediction in an individual case. We conclude that initial routine prospective molecular screening for AML1-ETO in all AMLs, combined with standardized morphological and immunological analysis, is desirable in order to produce improved prognostic stratification and to determine whether screening can ultimately be restricted to appropriate subgroups.     

The Feasibility of Fully Automated Pacemaker Advise in Treating Atrial Tachyarrhythmias

Background: Modern pacemakers continuously store significant cardiac‐related events. Interpreting these data and reprogramming the pacemaker can be time‐consuming and demands expert knowledge. A software‐based expert system, the therapy advisor (TA), was developed, which analyzes stored data and provides reprogramming recommendations. This study addresses whether pacemaker experts consider the messages that are automatically generated appropriate in the management of atrial tachyarrhythmias/atrial fibrillation (AT/AF). Methods: This observational, international, multicenter study follows 150 patients with suspected or documented atrial arrhythmias who received a dual‐chamber pacemaker (model Vitatron T‐70, Medtronic Inc., Minneapolis, MN, USA) incorporating the TA. The TA summarizes technical and clinical data stored in the pacemaker into key messages and may suggest programming changes. Twenty‐five cardiologists examined their patients per normal practice during two follow‐up visits. They reported the therapy changes they deemed necessary without initially reviewing the TA messages. Next, they rated their satisfaction with and the clinical relevance of the TA messages and recorded the final therapy changes. Results: The TA generated (mostly AT/AF‐related) main observations in 49% and programming advice in 33% of the patients. The experts rated 95% of the TA messages as satisfactory and deemed therapy changes necessary in roughly half the patients. Pacemaker changes in AT/AF therapy or general settings were prompted primarily by the diagnostic information stored in the device. Medication changes were mostly led by the symptoms reported by the patient. Conclusion: This study demonstrates that experienced cardiologists agree with 95% of the observations and programming suggestions that the TA automatically generates. (PACE 2010; 605–614)     

Renal Artery Aneurysm Exclusion Using a Self-Expanding Covered Stent with a Procedural Outcome and 6-Month Angiographic Follow-up

A 76-year-old woman with prior catastrophic rupture of a splenic artery aneurysm had a renal artery aneurysm discovered during evaluation of her refractory hypertension. The aneurysm was excluded using a coronary polytetrafluoroethylene (PTFE)-covered investigational (Symbiot) coronary stent in conjunction with coil occlusion of the inferior pole artery to preclude possible back flow into the excluded aneurysm. Six-month angiography demonstrated a patent vessel; her serum creatinine remained stable at 1.3 mg/dL.     

Conformational preferences and self-association modes of two diastereomeric statine derivatives

The conformational preferences and self-association modes of the two diastereomeric N-acetyl, methylamides of 3-hydroxy, 4-amino, 6-methylheptanoic acid (statine) with (R, S) and (S, S) configurations at the 3-hydroxy and 4-amino carbons, respectively, have been determined in solution as well as in the solid state by infrared absorption, ¹H nuclear magnetic resonance, and X-ray diffraction. Conformational energy computations have also been performed in parallel. In the crystal state, the change in chirality of the hydroxyl group induces different intermolecular H-bonding schemes in the (R, S) isomer compared to the two structurally distinct molecules in the asymmetric unit of the (S, S) isomer. Different propensities to self-aggregate are seen in solvents of low polarity. In solvents of high polarity, however, the molecules of both isomers are largely solvated, while still keeping some local conformational restriction. Conformational energy computations indicate that in vacuo the two diastereomers exhibit different flexibility, and a preferred conformation with a different type of intramolecular H-bond.     

T helper responsiveness in human Loa loa infection; defective specific proliferation and cytokine production by CD4+ T cells from microfilaraemic subjects compared with amicrofilaraemics

The proliferation and cytokine profiles of peripheral blood mononuclear cells (PBMC) from microfilaraemic (Mf⁺) subjects infected by Loa loa in response to antigens of several parasitic stages were compared with those from amicrofilaraemic (Mf⁻) individuals. While a strong lymphoproliferative response and consistent levels of both Th1 (IL-2, interferon-gamma (IFN-γ)) and Th2 (IL-4, IL-5) type cytokines were observed in response to adult worm (AW) and microfilariae (Mf) antigen in Mf⁻ individuals, Mf⁺ subjects were characterized by a T cell unresponsiveness, including proliferation, cytokine production and IL-2 mRNA expression. Conversely, T cell responsiveness to mitogens and non-specific antigen were similar in the two endemic populations. Depletion of lymphocyte subpopulations indicated that T CD4⁺ were mainly involved in the specific cellular response. In contrast to other cytokines, IL-10 was produced in response to all parasitic stages, in both Mf⁺ and Mf⁻ patients. Neutralization of IL-10 did not restore cytokine production in Mf⁺ patients, while B7 mRNA expression was similar between Mf⁺ and Mf⁻ subjects in response to Mf antigen, suggesting that IL-10 was not the only factor responsible for T cell unresponsiveness. Mf⁺ patients have lower Mf antigen-specific IgG levels compared with Mf⁻, and there is a significant correlation between Mf antigen-specific antibodies and IL-5 responses. These findings suggest that Mf⁻ status is correlated with T helper responsiveness, including proliferation and production of both Th1- and Th2-type cytokines, whereas Mf⁺ status is characterized by unresponsiveness of the same cell population, induced and/or maintained by microfilariae.     

Analysis of the immune response elicited by a Multiple Antigen Peptide (MAP) composed of two distinct protective antigens derived from the parasite Schistosoma mansoni

In this report we analyse the immune response elicited by a Multiple Antigen Peptide (MAP), containing three peptide sequences derived from two distinct vaccine candidates against schistosomiasis; the Schistosoma mansoni 28 kDa Gluthatione-S-Transferase (Sm28GST) and the Schistosoma mansoni Triose-Phosphate-Isomerase (sTPI). We examined the immunogenicity of this construct, named MAP 'DA', in three distinct mouse strains. The B-cell response, studied by measuring the production of different IgG isotypes, was mainly directed against the peptide derived from the Sm28GST, but also against the whole Sm28GST protein. In contrast, the T-cell response, as assessed by proliferation assay and cytokine mRNA expression, was directed against the MAP construct, the peptides derived from the sTPI protein and the whole sTPI protein. Significantly, T-cells from all MAP 'DA'-immunized mice, restimulated in vitro was the sTPI antigen, expressed IFN-γ specific messengers. This cytokine has been described to play a major role in the reduction of the Schistosoma mansoni pathology. We thus demonstrate that a single MAP construct, composed of peptides from distinct antigens of Schistosoma mansoni , induced a B- and T-cell response, including production of potentially protective IFN-γ, irrespective of the MHC background.     

Conformational study of cyclosporin A in acetone at low temperature

The conformation of cyclosporin A (CsA), an undecapeptide with seven N-methylated amino acids, was studied in acetone at 193 K. Previous studies of the conformation of CsA in different solvents, in the cyclosporin-cyclophilin complex and in complexes with LiCl showed that the conformation of the free and the bound CsA are different. Differences were observed at the conformation of the MeLeu⁹-MeLeu¹⁰ peptide bond, which is cis in solution and trans in the complex, and in the orientation of the amide protons and the N-Me groups. By using acetone, which is a proton acceptor, we wanted to influence the orientation of the amide protons. In the conditions used in this study a new conformation is found, which differs as well from the one previously observed in solution as from the Conformation observed in the complex. This conformation has a cis peptide bond between MeLeu⁹ and MeLeu¹⁰. The trans conformation of the peptide bond MeLeu⁹-MeLeu¹⁰, which is necessary for biological activity, was not induced. One of the amide protons is involved in an intramolecular H-bridge stabilising a β-turn around Sar³MeLeu⁴, and three of the seven NMe groups are oriented to the centre of the molecule. © Munksgaard 1994.     

Soluble interleukin-6 receptor (sIL-6R), a new prognostic factor in multiple myeloma

sIL-6R is a 55 kD soluble molecule mediating the interleukin-6 (IL-6) signal through the IL-6 receptor-associated transmembrane signal transducer, gp130. It has recently been suggested that sIL-6R serum levels may reflect disease severity in multiple myeloma (MM). We determined sIL-6R serum levels in 25 normal controls (NC) and in 80 MM patients at diagnosis and during the course of the disease. Measurements were done by ELISA. In NC, sIL-6R levels ranged from 14 to 40 ng/ml (median 28 ng/ml) whereas in MM patients the range was 10–200 ng/ml (median 38 ng/ml) ( P  < 0.01). 61 patients entered remission and 19 were resistant. Median sIL-6R value at diagnosis was 36 ng/ml (10–120) in responding patients, and 82 ng/ml (20–200) in non-responding patients ( P  < 0.001). During a follow-up from 12 to 89 months, sIL-6R values remained more or less stable in most patients. High sIL-6R levels correlated with poor survival.