High cyclin-dependent kinase inhibitors in Bcl-2 and Bcl-xL-expressing CD34+-proliferating haematopoietic progenitors

We have previously described the isolation of primitive, slow-proliferating progenitors from normal, circulating CD34+ cells by using the fluorescent dye 5-6-carboxyfluorescein diacetate succinimidyl ester (CFDA-SE). CFDA-SE(bright) (primitive) and CFDA-SE(dim) (differentiating) cells were isolated following cytokine stimulation on the basis of their different proliferation rates. In the present work we analysed the expression levels of a number of proteins involved with differentiation, proliferation and survival/apoptosis in CFDA-SE(bright)/CD34+/slow-proliferating cells that were previously defined as progenitors capable of differentiating into different lineages. The aim of this work was to gain a better understanding of our model system in order to define some of the important parameters that regulate differentiation in haematopoietic progenitors. GATA-1 and PU.1 RNA levels were similar in freshly isolated (d 0) CD34+ and in CFDA-SE(bright) (bright) cells, whereas they increased in CFDA-SE(dim) (dim) cells. Accordingly, Nm23 was expressed at higher levels in bright cells. Moreover, bright cells had higher p21WAF1/CIP1, p27KIP1 and p16Ink4 protein levels than dim cells. Consistently, Cdc2 and Cdk2 kinase activity was much higher in the dim than in the slower proliferating bright cells. C-myc and p53 levels were higher in bright cells than in d 0 CD34+ and dim cells, and so was Bcl-xL, which followed the trend we have previously described for Bcl-2. Thus, bright cells, despite having a higher proliferation rate than the starting d 0 CD34+ population, have strikingly elevated levels of cyclin-dependent kinase inhibitors, which are likely to also act as inhibitors of differentiation.     

Intracranial atheromatous disease treatment with the Wingspan stent system: Evaluation of clinical,procedural outcome and restenosis rate in a single-center series of 21 consecutive patients with acute and mid-term results

Background

Intracranial atherosclerosis may be the underlying pathology in up to 15% of ischemic strokes, but may account for about 40% of strokes in some populations. After an ischemic event determined by intracranial atherosclerosis, patients have a 12% annual risk of stroke recurrence, mostly during the first year.

Objective

To evaluate procedural safety, clinical outcome and restenosis rate of Wingspan stent placement.

Methods

Twenty-one caucasoid patients were enrolled. Target patients were affected by high-grade, symptomatic, intracranial atherosclerotic lesions, were on antithrombotic therapy and at high stroke risk. All patients were treated with the Wingspan stent system.

Results

Technical success resulted 100%, with all target lesions being reduced to < 50%. No stroke or death were observed at 30.The mean percent of stenosis was reduced from a middle value of 84% to a middle value of 17% after stent placement. Medium follow-up was 19.5 months (range 6–36 months). No stroke or death occurred in any patient. None of the patients presented a <50% stent patency rate at follow-up.

Conclusions

The short-term results and follow up analysis provide evidence demonstrating the safety of the Wingspan system when used in high-risk patient population. Due to concerns regarding long-term stent patency and ischemic events occurrence emerged from clinical trials such as the SAMMPRIS, intracranial angioplasty and stent with the Wingspan system should be considered only for high risk patients in which it may be considered the only viable therapeutic option.     

alpha-Dystroglycan does not play a major pathogenic role in autosomal recessive hereditary inclusion-body myopathy

Mutations of the GNE gene are responsible for autosomal recessive hereditary inclusion-body myopathy (HIBM). In this study we searched for the presence of any significant abnormality of alpha-dystroglycan (alpha-DG), a highly glycosylated component of the dystrophin-glycoprotein complex, in 5 HIBM patients which were previously clinically and genetically characterized. Immunocytochemical and immunoblot analysis showed that alpha-DG extracted from muscle biopsies was normally expressed and displayed its typical molecular mass. Immunoblot analysis on the wheat germ lectin-enriched glycoprotein fraction of muscles and primary myotubes showed a reduced amount of alpha-DG in 4 out of 5 HIBM patients, compared to normal and other diseased muscles. However, such altered lectin-binding behaviour, possibly reflecting a partial hyposialylation of alpha-DG, did not affect the laminin binding properties of alpha-DG. Therefore, the subtle changes within the alpha-DG glycosylation pattern, detected in HIBM muscles, likely do not play a key pathogenic role in this disorder.     

The effect of disease activity on leptin, leptin receptor and suppressor of cytokine signalling-3 expression in relapsing-remitting multiple sclerosis

In this study we observed higher serum leptin levels in relapsing-remitting multiple sclerosis (RRMS) patients during remission than in controls. The expression of leptin receptor (ObR) was higher in CD8+ T cells and monocytes from RRMS patients in relapse than in patients in remission and in controls. Relapsing patients showed high levels of pSTAT3 and low expression of SOCS3 and leptin administration induced an up-regulation of pSTAT3 only in monocytes from patients in relapse. Our data suggest that ObR may be involved in the development of clinical relapses in RRMS patients and suggest a rationale for potential targeting of the leptin axis during MS.     

High-dose calcitriol therapy and progression of cardiac vascular calcifications

BACKGROUND: Dialysis patients show a very high prevalence of cardiovascular complications, affected as they are with abnormal and accelerated vascular calcifications and, eventually, calcium and phosphorous metabolism disorders. Multislice computed tomography (MSCT) provides a reproducible, high-resolution imaging of calcium contained in cardiac arteries, measured by Agatston score. The aim of the present study was to evaluate the influence of high-dose and low-dose calcitriol therapy on the progression of cardiac vascular calcifications in dialyzed patients. METHODS: We enrolled 36 dialyzed patients in a prospective study, including an interventional period of 12 months and a follow-up period of 12 months. Eighteen protocol patients received intravenous pulses of high-doses calcitriol at the end of dialytic treatment and sevelamer hydrochloride therapy. Control patients received low-dose calcitriol and sevelamer hydrochloride as well. Two MSCT scans were performed: 1 at the start of the study and 1 at the end of follow-up, and Agatston score was calculated at both examinations. RESULTS: At first examination, protocol patients showed almost the same level of cardiac vascular calcification as control patients. At the second MSCT, statistically significantly higher values of Agatston score were recorded for all patients. Indeed, patients who showed higher baseline values developed worse calcifications as recorded at the end of follow-up, both in the protocol and control group. CONCLUSIONS: Our data show that baseline level is strongly predictive of vascular calcification progression, and, moreover, there is no association between calcitriol administered doses and the progression of cardiac vascular calcification.     

Deletions of the cyclin-dependent kinase inhibitor genes p16INK4A and p15INK4B in non-Hodgkin's lymphomas

The tumor suppressor genes p16INK4A and p15INK4B map to the 9p21 chromosomal locus and are either homozygously deleted or mutated in a wide range of human cancer cell lines and tumors. Although chromosome 9 abnormalities have been described in non-Hodgkin's lymphomas (NHLs), to date, the mutational status of these genes has not been determined for these malignancies. A total of five cell lines and 75 NHLs were examined for homozygous deletions or point mutations in the coding regions of both the p15 and p16 genes using Southern blot and/or polymerase chain reaction-single-strand conformation polymorphism analyses. Homozygous deletions of either the p16 gene or both the p15 and p16 genes were observed in one diffuse large B-cell lymphoma cell line and two uncultured lymphomas consisting of one large B-cell and one mixed T-cell lymphoma. In contrast, point mutations were not detected in either the cell lines or lymphomas. These results indicate that the rate of alterations in the p15 and p16 genes is low for lymphomas, but loss of p16 and/or p15 may be involved in the development of some lymphomas.