Cell cycle reentry triggers hyperploidization and synaptic dysfunction followed by delayed cell death in differentiated cortical neurons.

Cell cycle reentry followed by neuronal hyperploidy and synaptic failure are two early hallmarks of Alzheimer's disease (AD), however their functional connection remains unexplored. To address this question, we induced cell cycle reentry in cultured cortical neurons by expressing SV40 large T antigen. Cell cycle reentry was followed by hyperploidy in ~70% of cortical neurons, and led to progressive axon initial segment loss and reduced density of dendritic PSD-95 puncta, which correlated with diminished spike generation and reduced spontaneous synaptic activity. This manipulation also resulted in delayed cell death, as previously observed in AD-affected hyperploid neurons. Membrane depolarization by high extracellular potassium maintained PSD-95 puncta density and partially rescued both spontaneous synaptic activity and cell death, while spike generation remained blocked. This suggests that AD-associated hyperploid neurons can be sustained in vivo if integrated in active neuronal circuits whilst promoting synaptic dysfunction. Thus, cell cycle reentry might contribute to cognitive impairment in early stages of AD and neuronal death susceptibility at late stages.

Identification and dynamics of polyglycine II nanocrystals in Argiope trifasciata flagelliform silk.

Spider silks combine a significant number of desirable characteristics in one material, including large tensile strength and strain at breaking, biocompatibility, and the possibility of tailoring their properties. Major ampullate gland silk (MAS) is the most studied silk and their properties are explained by a double lattice of hydrogen bonds and elastomeric protein chains linked to polyalanine ß-nanocrystals. However, many basic details regarding the relationship between composition, microstructure and properties in silks are still lacking. Here we show that this relationship can be traced in flagelliform silk (Flag) spun by Argiope trifasciata spiders after identifying a phase consisting of polyglycine II nanocrystals. The presence of this phase is consistent with the dominant presence of the -GGX- and -GPG- motifs in its sequence. In contrast to the passive role assigned to polyalanine nanocrystals in MAS, polyglycine II nanocrystals can undergo growing/collapse processes that contribute to increase toughness and justify the ability of Flag to supercontract.

[CT imaging features of bronchiolitis]. / Aspect TDM des bronchiolites.

Bronchiolitis may be encountered in numerous clinical circumstances. Previous history of smoking, infections, toxic exposure, immunodeficiency, chronic inflammatory disorders or transplantation must be known. CT findings consist in centrilobular micronodules with sharp or ill borders of various density and/or a mosaic attenuation with expiratory air trapping. Tree-in-bud pattern suggest an inflammatory or infectious bronchiolitis. The associated presence of bronchiectasis and bronchiolectasis must be considered. Imaging-pathologic correlations will be presented for inflammatory bronchiolitis (infectious bronchiolitis, hypersensitivity pneumonitis, respiratory bronchiolitis, follicular bronchiolitis, diffuse panbronchiolitis) and fibrosing bronchiolitis (constrictive bronchiolitis, post-infectious bronchiolitis, toxic fume exposure, transplant-related bronchiolitis).

Prognostic value of minimal residual disease (MRD) in acute myeloid leukemia (AML) with favorable cytogenetics [t(8;21) and inv(16)].

Most patients with acute myeloid leukemia (AML) and t(8;21) or inv(16) have a good prognosis with current anthracycline- and cytarabine-based protocols. Tandem analysis with flow cytometry (FC) and real-time RT-PCR (RQ-PCR) was applied to 55 patients, 28 harboring a t(8;21) and 27 an inv(16), including one case with a novel CBFbeta/MYH11 transcript. A total of 31% (n=17) of CR patients relapsed: seven with t(8;21) and 10 with inv(16). The mean amount of minimal residual disease (MRD) detected by FC in relapsed and nonrelapsed patients was markedly different: 0.3 vs 0.08% (P=0.002) at the end of treatment. The mean number of fusion transcript copies/ ABL x 10(4) also differed between relapsed and non-relapsed patients: 2385 vs 122 (P=0.001) after induction, 56 vs 7.6 after intensification (P=0.0001) and 75 vs 3.3 (P=0.0001) at the end of chemotherapy. Relapses were more common in patients with FC MRD level >0.1% at the end of treatment than in patients with < or = 0.1%: cumulative incidence of relapse (CIR) was 67 and 21% (P=0.03), respectively. Likewise, using RQ-PCR, a cutoff level of >10 copies at the end of treatment correlated with a high risk of relapse: CIR was 75% for patients with RQ-PCR >10 compared to 21% for patients with RQ-PCR levels < or = 10 (P=0.04). Combined use of FC and RQ-PCR may improve MRD detection, and provide useful clinical information on relapse kinetics in AML patients.

Adverse prognostic impact of CD36 and CD2 expression in adult de novo acute myeloid leukemia patients.

BACKGROUND AND OBJECTIVES: A consecutive series of acute myeloid leukemias (AML) patients was analyzed in conditions which reduce the inter-assay variations (the same flow cytometer, the same observers and the same panel of monoclonal antibodies) in order to investigate the prognostic information provided by flow cytometry. DESIGN AND METHODS: Two hundred and sixty-six bone marrow (BM) samples from 326 patients enrolled in the LMA-99 protocol from the CETLAM group were studied by multiparametric flow cytometry. Immunophenotyping studies were performed on erythrocyte-lysed BM samples. Antigen expression of leukemic cells was analyzed using triple stainings with fluorochrome-conjugated combinations of monoclonal antibodies. RESULTS: CD2 was positive in 21 cases (8%); an associated inv(16) was detected in eight CD2+ cases (38%). Two-year overall survival (OS) rate for CD2+/inv(16)+ patients was 75%, whereas it was 0% for CD2+/inv(16)- patients and 47% for CD2- patients (p=0.0001). CD36 was expressed in 37% of patients (n=98). Two-year leukemia-free survival (LFS) rate was 34% for CD36+ patients and 55% for CD36- patients (p=0.001). In the multivariate analysis, CD2+ (RR=8.4; p=0.0001) and adverse karyotype (RR=10.2; p=0.0001) were associated with a lower CR rate, CD36+ (RR=1.5; p=0.03), CD2+ (RR=2; p=0.04) and adverse karyotype (RR=4; p=0.0001) were associated with a lower OS and CD36+ (RR=2; p=0.002) and adverse karyotype (RR=3.5; p=0.005) predicted a lower LFS. CONCLUSIONS: CD2+ patients had a very poor OS when CD2/inv(16)+ cases were excluded. CD36 and CD2 expression at diagnosis can provide prognostically important information in adult de novo AML.

Prognostic indexes in follicular lymphoma: a comparison of different prognostic systems.

BACKGROUND: The International Prognostic Index (IPI), initially designed for aggressive lymphomas, is also used in follicular lymphoma (FL) and other indolent lymphomas. Two new prognostic indexes have recently been proposed for FL [the Italian Lymphoma Intergroup (ILI) Index and the Follicular Lymphoma International Prognostic Index (FLIPI)]. PATIENTS AND METHODS: Three indexes, IPI [age >60 years, extranodal involvement two or more sites, elevated lactate dehydrogenase (LDH), Eastern Cooperative Oncology Group performance status > or =2, stage > or =3], ILI (age >60 years, extranodal involvement two or more sites, elevated LDH, male sex, B symptoms, erythrocyte sedimentation rate > or =30 mm first hour) and FLIPI (age >60 years, stage > or =3, elevated LDH, nodal involvement five or more, haemoglobin level < or =12 g/dl) were calculated in 411 patients with FL. RESULTS: Overall concordance between the three indexes was 54%. A total of 126 (31%) patients were included in the high-risk group according to IPI, 131 (32%) according to ILI and 157 (38%) after FLIPI application. Ten-year overall survival rates after applying the prognostic indexes (IPI, ILI and FLIPI) were, respectively: 72%, 71% and 72%, in the low-risk group; 51%, 60% and 49% in the intermediate-risk group; and 24%, 16% and 31% in the high-risk group. CONCLUSIONS: In this series, all three indexes, IPI, ILI and FLIPI, were useful to classify FL patients into differentiated risk groups, although the FLIPI identified a larger proportion of high-risk patients than the IPI and ILI.

Predictive value of Follicular Lymphoma International Prognostic Index (FLIPI) in patients with follicular lymphoma at first progression.

BACKGROUND: Different prognostic scores have been proposed to predict the outcome of follicular lymphoma (FL) patients at diagnosis. A new prognostic index specifically addressing FL patients, the Follicular Lymphoma International Prognostic Index (FLIPI), has recently been developed, which might also be useful in patients with progression. PATIENTS AND METHODS: One hundred and three patients (55 male, 48 female; median age 59 years) with FL in first relapse/progression after an initial response to therapy (50 complete responders/ 53 partial responders) were included in the study. RESULTS: Five-year survival from progression (SFP) was 55% (95% confidence interval 44%-66%). The distribution according to the FLIPI at relapse was 39% good prognosis, 24% intermediate prognosis and 37% poor prognosis. Five-year SFP for these groups were 85%, 79% and 28%, respectively (P < 0.0001). Other variables at relapse with prognostic significance for SFP were age, presence of B symptoms, performance status, bulky disease, number of involved nodal sites, lactate dehydrogenase level, hemoglobin level, histological transformation, the Italian Lymphoma Intergroup prognostic index for FL and the International Prognostic Index for aggressive lymphomas. In the multivariate analysis bulky disease (P=0.01), presence of B symptoms (P=0.03) and FLIPI at relapse (P=0.0003) were the most important variables for predicting SFP. CONCLUSIONS: In patients with FL at first relapse/progression, the FLIPI, along with the presence of bulky disease and B symptoms, are features that predict SFP and thus could be useful to select candidates for experimental treatments.

Clinical utility of bone marrow flow cytometry in B-cell non-Hodgkin lymphomas (B-NHL).

AIM: To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated. METHODS AND RESULTS: Morphological analysis and FC immunophenotyping were performed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard kappa/lambda/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances. CONCLUSIONS: Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients.

Predictive factors for a successful mobilization of peripheral blood CD34+ cells in multiple myeloma.

We analyzed the prognostic factors for a successful mobilization and peripheral blood stem cell collection in a series of 57 consecutive patients with multiple myeloma (MM); a new scoring system to predict an adequate mobilization in this subset of patients was also constructed. A total of 221 aphereses were performed in 57 patients with MM. The median time from diagnosis to mobilization was 12 months (range 4-120). Only one line of chemotherapy was administered before mobilization to 36 patients and two or more to 21. The median number of alkylating chemotherapy cycles was 6 (2-33). Two patients were mobilized in complete remission, 32 in partial response, and 23 in stable/progressive disease. Significant adverse prognostic factors for collecting 2.5 x 10(6) CD34+cells/kg or more were: a period of at least 12 months from diagnosis, at least six cycles of alkylating agents, and a plasma cell infiltration of 20% or more prior to mobilization. Patients with three risk factors had a probability of only 0.38 (95% CI 0.3-0.9) for adequate mobilization. Ten patients failed to mobilize; a period from diagnosis of 12 months or more and female sex were unfavorable factors. Patients with two risk factors had a probability of 0.50 (95% CI 0.2-0.8) for failing the mobilization procedure. These findings indicate that MM patients must be mobilized early in the course of the disease, with minimal disease burden before severe hematopoietic progenitor cell injury due to cumulative therapy.

Bronchoscopy guided by high-resolution computed tomography for the diagnosis of pulmonary infections in patients with hematologic malignancies and normal plain chest X-ray.

BACKGROUND AND OBJECTIVES: High-resolution computed tomography (HRCT) of the chest is able to demonstrate the presence of pulmonary infiltrates in febrile neutropenic patients with normal chest X-rays. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is a safe procedure for the etiological diagnosis of pulmonary infiltrates in oncohematologic patients. The objective of this study was to determine the diagnostic yield and subsequent therapeutic changes of a protected BAL (p-BAL) guided by HRCT in febrile oncohematologic patients unresponsive to broad-spectrum antibiotics with a normal chest X-ray. DESIGN AND METHODS: Twenty-two episodes from 20 oncohematologic patients were included: group A, 9 episodes (8 patients) with no respiratory symptoms and group B, 13 episodes (12 patients) with signs or symptoms of pulmonary infection. HRCT and p-BAL were performed in all episodes within the first 24 hours. RESULTS: HRCT showed abnormalities in all 22 episodes (bilateral abnormalities in 14 of the 22 episodes [64%]) and the most frequent pattern was ground-glass infiltrate (7 out of 22 episodes). An infectious agent was isolated in 12 of the 22 episodes, 5 in group A and 7 in group B with a diagnostic yield of 54%. Antimicrobial therapy was modified in 12 of the 22 episodes (54%): 5 in group A and 7 in group B. In 6 episodes, treatment was changed according to HRCT results and in the remaining 6 due to positive microbiologic results. Modifications in empirical therapy were associated with a favorable response in 44% episodes of group A and in 31% of group B. INTERPRETATION AND CONCLUSIONS: Oncohematologic patients with fever of unknown origin unresponsive to empirical antibiotics and with a normal chest X-ray can be candidates to undergo a HRCT. This subgroup of high-risk patients can benefit from a combined strategy consisting of BAL guided by a previous HRCT.

Mobilization kinetics of peripheral blood progenitor cells after IAPVP-16 salvage chemotherapy plus G-CSF in lymphoproliferative disorders.

We have explored the efficacy of salvage chemotherapy combination, IAPVP-16 (ifosfamide 5 g/m2 on day 1; VP-16 100 mg/m2 on days 1-3; ara-C 1.2 g/m2/12 h on days 1 and 2; methylprednisolone 80 mg/m2 on days 1-5) plus G-CSF for PBPC mobilization. This protocol was used in 45 patients with relapsed or refractory lymphoproliferative diseases who underwent 85 leukaphereses. In 41 patients > 2 x 106/kg CD34+ cells were obtained after a median of two procedures. The median number of CD34+ cells harvested was 3.2 x 106/kg per apheresis and 8.4 x 106/kg per patient. Seven of 10 patients who had failed previous mobilization attempts achieved more than 2 x 106 CD34+ cells/kg in a maximum of three aphereses. A history of previous mobilization failure and a low platelet count (<150 x 109/l) negatively influenced the CD34+ cell yield in univariate and multivariate analyses. A good correlation was found between the circulating CD34+ cells/microl and the CD34+ cells and CFU-GM in the leukaphereses products (r = 0.93 and r = 0.73, P < 0.001), and > or =17 CD34+ cells/microl predicted the achievement of > 2 x 106/kg CD34+ cells in a single leukapheresis in more than 90% of cases. IAPVP-16 plus G-CSF may be specially indicated in tandem transplantations or CD34+ selection and in patients who have failed previous mobilization attempts.