V180I mutation of the prion protein gene associated with atypical PrP glycosylation

A valine to isoleucine mutation at residue 180 was identified in a French patient with Creutzfeldt-Jakob disease (CJD). The mutation is located in the close vicinity of one of the two N-glycosylation sites of the cellular prion protein (PrP^C). Western blot analysis revealed accumulation in the brain of the pathogenic proteinase K-resistant PrP (PrP^Sc) isoform with the notable absence of the diglycosylated band. The mutant protein expressed in CHO cells was correctly glycosylated, suggesting that the atypical glycosylation pattern of PrP^Sc was not due to the mutation at position 180. These results suggest that the diglycosylated form of the mutant PrP^180I prevents its conversion into the pathogenic mutant form PrP^Sc180I, supporting a central role of N-linked glycan chains in the PrP conversion process.     

Evaluation of the professional practices of physicians in transfusion technology and medicine]

The evaluation of the professional practices (EPP) is obligatory for all the physicians since July 1, 2005 for a first five-year period. It represents one of the components of the continuous medical training (CMT). The French Society of Blood Transfusion and National Institute of Blood Transfusion are the promoters of the EPP in transfusion technology and medicine. Initially, the programs of EPP will be conceived and controlled by experts and will relate to their basic activities. During a five years cycle, the physician taking part in a program must validate a specific action and take part in a rolling programme. At the end of the programme, the physician will receive a certificate issued by National Institute of Blood Transfusion and will have to submit it to a committee placed under the responsibility of the regional physicians' committee.     

A longitudinal and prospective study of Epstein-Barr virus load in AIDS-related non-Hodgkin lymphoma.

BACKGROUND: Epstein-Barr virus (EBV) may be causally associated with non-Hodgkin Lymphoma (NHL) in HIV-infected patients. OBJECTIVES: To compare EBV load in whole blood in AIDS-NHL patients, HIV non-AIDS patients and non-HIV-infected persons, and to prospectively measure EBV load in whole blood in AIDS-NHL patients. STUDY DESIGN: Longitudinal and prospective study. RESULTS: We observed no statistical difference in EBV load between AIDS-NHL (3.69log(10) copies/mL [interquartile range (IQR): 2.89-4.27]) and HIV non-AIDS patients (3.08log(10) copies/mL [IQR: 1.29-3.57]) but AIDS-NHL patients had significantly higher EBV loads than HIV-negative controls (1.19log(10) copies/mL [IQR: 0.00-3.29]). We noticed an inverse correlation between CD4+ lymphocytes count and EBV load in patients with AIDS-NHL (r(2)=0.41, P=0.01). In the longitudinal study, the mean EBV load three months after NHL diagnosis decreased significantly (mean difference=-1.69log(10) copies/mL [95% confidence interval: -0.32; -3.04]; P=0.03) under chemotherapy but was still elevated in patients with relapses or no response to chemotherapy. CONCLUSION: Although EBV load seems a suboptimal marker for the diagnosis of AIDS-NHL, we observed a significant decrease of EBV load in patients treated with chemotherapy and a strong association between NHL outcome and EBV load in whole blood.     

Characterization of cells with a high aldehyde dehydrogenase activity from cord blood and acute myeloid leukemia samples

Aldehyde dehydrogenase (ALDH) is a cytosolic enzyme that is responsible for the oxidation of intracellular aldehydes. Elevated levels of ALDH have been demonstrated in murine and human progenitor cells compared with other hematopoietic cells, and this is thought to be important in chemoresistance. A method for the assessment of ALDH activity in viable cells recently has been developed and made commercially available in a kit format. In this study, we confirmed the use of the ALDH substrate kit to identify cord blood stem/progenitor cells. Via multicolor flow cytometry of cord blood ALDH+ cells, we have expanded on their phenotypic analysis. We then assessed the incidence, morphology, phenotype, and nonobese diabetic/ severe combined immunodeficiency engraftment ability of ALDH+ cells from acute myeloid leukemia (AML) samples. AML samples had no ALDH+ cells at all, an extremely rare nonmalignant stem/progenitor cell population, or a less rare, leukemic stem cell population. Hence, in addition to identifying nonmalignant stem cells within some AML samples, a high ALDH activity also identifies some patients' CD34+/ CD38- leukemic stem cells. The incidence of normal or leukemic stem cells with an extremely high ALDH activity may have important implications for resistance to chemotherapy. Identification and isolation of leukemic cells on the basis of ALDH activity provides a tool for their isolation and further analysis.     

Korrelation histologischer und nuklearmedizinischer Befunde der Tumorregression in behandelten bösartigen Lungentumoren

Zusammenfassung Die CT ist nach neoadjuvanter Radio-Chemo-Therapie zur Charakterisierung der Tumorregression nur begrenzt einsetzbar. Daher sollte die Wertigkeit der ¹⁸F-FDG-PET als molekulares, nichtinvasives bildgebendes Verfahren analysiert werden.Bislang 32/100 Patienten mit NSCLC Stadium IIIA/IIIB wurden in einer multizentrischen, randomisierten Therapiestudie (LUCAS-MD) untersucht. Prätherapeutisch erfolgten eine ¹⁸F-FDG-PET und eine Spiral-CT. Der neoadjuvante Therapieblock bestand aus 2–3 Zyklen Paclitaxel und Carboplatin sowie einer simultanen Radio-Chemo-Therapie. Es folgte eine zweite PET direkt vor der Operation mit Bestimmung des Glukosemetabolismus für Primärtumor und Lymphknotenmetastasen sowie eine PET-CT-Bildfusion. Der am OP-Präparat bestimmte Regressionsgrad wurde mit den PET-Befunden und dem Überleben der Patienten korreliert.In Lymphknoten von 10 Patienten mit kompletter Remission in der FDG-PET zeigte sich ein Regressionsgrad/RG III im OP-Präparat (Sensitivität 100%). Zu 94% wiesen die 16/32 Patienten mit kompletter Remission im Primärtumor RG IIb oder III auf, ein Patient RG IIa (falsch-negativ). Die Zweijahresüberlebenswahrscheinlichkeit bei kompletter Remission war nach 24 Monaten signifikant erhöht (76 vs. 20%, p=0,0079). Patienten mit RG III bzw. IIb lebten signikant länger als Patienten mit RG IIa bzw. I (63 vs. 36%, p=0,0123).Der RG korreliert mit der in der FDG-PET bestimmten metabolischen Remission. Die PET eilt metabolisch dem durch die CT bestimmten Tumoransprechen nach neoadjuvanter Behandlung deutlich voraus und ermöglicht wahrscheinlich eine prospektive Aussage über den Langzeittherapieerfolg von Patienten mit NSCLC im Stadium III.     

Error negativity on correct trials: a reexamination of available data

The error negativity, an EEG wave observed when subjects commit an error in a choice reaction time (RT) task, is often considered as a sign of error detection. Recently, reports of Ne-like waves on correct responses did challenge this interpretation. It has been proposed, however, that these Ne-like waves result either from an artifactual contamination of response-locked activities by stimulus-locked ones, or from an implicit monitoring of the time elapsing during the RT. Our aim was to reprocess published data: (1) to compare the shape and amplitude of EMG-locked and stimulus-locked ERPs on correct trials, and (2) to compare the size of the EMG-locked Ne-like waves obtained on fast and slow trials. The results neither support the artifact hypothesis nor the RT monitoring one. Therefore, it seems that the Ne-like waves observed on correct trials do correspond to a Ne, which suggests that the Ne has a broader significance than just error detection.     

Identification of iduronate sulfatase gene alterations in 70 unrelated Hunter patients

We studied 70 unrelated Hunter patients and found a gene alteration in every patient. The molecular heterogeneity was very important. Large gene rearrangements were identified in 14 patients. Forty-three different mutations were identified in the 56 other patients and 31 were not previously described. Deletions and insertions, splice site mutations were associated with a severe phenotype as nonsense mutations except Q531X. Only a few mutations were present in several patients making difficult genotype-phenotype correlations. Mutation identification allows accurate carrier detection improving prenatal diagnosis. The mother was not found to be a carrier in five cases among the 44 sporadic cases. Haplotype analysis demonstrated a higher frequency of mutations in male meiosis.     

Gap junction communication between cells aggregated on a cellulose-coated polystyrene: influence of connexin 43 phosphorylation

The appropriate functioning of tissues and organ systems depends on intercellular communication such as gap junctions formed by connexin (Cx) protein channels between adjacent cells. We have previously shown that Swiss 3T3 cells aggregated on hydrophilic cellulose substratum Cuprophan (CU) establish short linear gap junctions composed of Cx 43 in cell surface plaques. This phenomenon seems to depend on the high intracellular cyclic AMP (cAMP) concentration triggered by attachment of the cells to CU. We have now used a cellulose-coated polystyrene inducing the same cell behaviour to analyse the gap junction communication between aggregated cells. The transfer of the dye Lucifer Yellow (LY) between cells showed that cells aggregated on cellulose substratum rapidly (within 90 min) establish functional gap junctions. Inhibitors of cAMP protein kinase (PKI) or protein kinase C (GF109203X) both inhibited the diffusion of LY between neighbouring cells. Western blot analysis showed that this change in permeability was correlated with a decrease in Cx 43 phosphorylation. Thus, cellulose substrata seem to induce cell-cell communication through Cx 43 phosphorylation modulated by PKA and PKC. To understand the mechanisms by which a substratum regulates gap junctional communication is critically important for the emerging fields of tissue engineering and biohybrid devices.