Wilms' tumor gene 1 transcript levels in leukapheresis of peripheral blood hematopoietic cells predict relapse risk in patients autografted for acute myeloid leukemia

Autologous hematopoietic stem cell transplantation (ASCT) is a curative option alternative to allogeneic transplantation for patients with acute myeloid leukemia (AML). Relapse after ASCT can be due to contamination with leukemic blasts of autologous peripheral blood stem cells (PBSCs) collected by leukapheresis (LK). Identification and quantification of a minimal residual disease (MRD) marker in PBSCs could be relevant in determining the relapse risk after ASCT. High levels of the WT1 gene transcript in bone marrow of AML patients after treatment completion predict disease relapse. We evaluated WT1 transcript levels in autologous PBSC from LK used for ASCT in 30 consecutive AML patients in complete remission (CR) and established a correlation with clinical outcome. At diagnosis, all patients had WT1 overexpression. All patients were in morphological and genetic CR at the time of PBSC collection and before ASCT. Real-time quantitative PCR of WT1 was performed in samples of each LK, using TaqMan technology on RNA from mononucleated cells. The median WT1 transcript level in the PBSC graft (WT1-LK) of patients who relapsed was significantly higher than of those who did not relapse after transplantation (P <.0001). We defined a cut-off level of 80 WT1-LK copies/ABL 10e4 copies to discriminate between positive and negative PBSC grafts. The cut-off level was strongly associated with disease recurrence, DFS and OS. Our study represents the largest series of patients evaluating WT1 as a marker of MRD in PBSC LK products using a completely standardized real-time WT1-reverse transcriptase-PCR based assay. These data, if confirmed by prospective study, will help to determine an individual patient's adapted postremission allocation strategy.

Predicting aneuploidy in human oocytes: key factors which affect the meiotic process

BACKGROUND

To estimate the incidence of aneuploidy in relation to patients' characteristics, the type of hormonal stimulation and their response to induction of multiple follicular growth, 4163 first polar bodies (PB1s) were analyzed.

METHODS

Five hundred and forty four infertile couples underwent 706 assisted conception cycles (640 with poor prognosis indications and 66 controls) in which chromosomal analysis of PB1 for the chromosomes 13, 15, 16, 18, 21 and 22 was performed. Results were evaluated in a multivariate analysis.

RESULTS

The proportion of normal oocytes was directly correlated (P < 0.01) with (i) the number of mature oocytes and (ii) the establishment of a clinical pregnancy; and inversely correlated (P < 0.01) with (i) female age, (ii) causes of female infertility (endometriosis, abortions, ovulatory factor), (iii) poor prognosis indications (female age, number of previous cycles, multiple poor prognosis indications), (iv) number of FSH units per oocyte and (v) number of FSH units per metaphase II oocyte. There was a weak significance of frequency (P < 0.05) between type of abnormality (originated by chromatid predivision, chromosome non-disjunction or combined mechanisms in the same oocyte) and groups of the studied variables, rather than to a specific abnormality or a specific chromosome.

CONCLUSIONS

The type of infertility had a significant effect on errors derived from the first meiotic division, whose incidence was significantly higher in the presence of endometriosis or of an ovulatory factor, and in women that experienced repeated abortions. Each aneuploidy event was found to be dependent not on a specific variable, but on groups of variables. In addition, the tendency of chromosomal abnormalities to occur simultaneously implies that the deriving aneuploidies can be of any type.

Capillary blood viscosity in microcirculation

As known, at the arteriolar level there is the highest resistance to the flow due to the section and to the velocity with an average pressure fall of 50 mmHg (from 85 to 35 mmHg). This resistance is expressed in sec(-1) by the ratio W/2r. This ratio is very high with an average value of 332 sec(-1) and viscosity at this high shear-rate is negligible. At the capillary level the pressure fall is 11.5 mmHg but the vascular resistance W/2r is much lower, on average 32 sec(-1). We can say that if a resistance of 333 sec(-1) corresponds with a pressure fall of 50 mmHg, then a resistance of 32 sec(-1) should correspond with a pressure fall of 4.8 mmHg. The highest pressure fall is due to another kind of resistance which we can define as "Capillary Blood Viscosity" because it depends on the rheological and structural characteristics of the blood. Our instrument reproduces the structure of the capillary district in an experimental model and measures the General Blood Viscosity (GBV) and the Capillary Blood Viscosity (CBV) at the same shear-rate and in particular at the low shear-rate when in non-Newtonian fluids the highest increase in viscosity appears. Consequently, at the capillary, viscosity is dominant with respect to the other geometric and physical resistances. Moreover, the percentage ratio between the GBV and the CBV gives a physical measure of erythrocyte deformability. Knowing viscosity at shear-rate present in the circulatory system, we can obtain the size of RBCs aggregates in the different circulatory districts and their characteristics expressed like "aggregation bond". Changes in CBV are the only possibility in clinical practice to improve the circulatory flow in the capillary district because it is not sure that changes in the arteriolar section can improve the capillary flow or rather open arterio-venous anastomosis. Moreover, in the systemic circulation the aggregate size allows us to point out the phenomenon of cell adhesion because the presence of several receptors involves also the other blood cells. Finally the size and the stability of the RBCs aggregates can modify the endothelial thrombo-resistance.

Do static or dynamic AFOs improve balance?

OBJECTIVE

To verify if partial or total limitation of degrees of freedom at ankle joints could help patients with balance disorders in standing and walking.

DESIGN

A cross-over design was chosen. Patients with multiple sclerosis (MS) were tested in three experimental conditions: barefooted, wearing ankle foot orthoses (AFOs), and wearing AFOs that allowed plantar flexion.

SETTING

Neurorehabilitation unit in a rehabilitation centre.

SUBJECTS

Fourteen patients suffering from MS with mild strength problems and balance disorders that required them to use walking aids outside.

MAIN OUTCOME MEASURES

Tests inferring static and dynamic skills were carried out in the three experimental conditions described above.

RESULTS

Improvements were obtained in static balance tests especially wearing dynamic AFOs; the number of patients who were able to pass tasks on balance in upright position such as 'standing with feet together, head extended' increased from three to nine. Dynamic balance was impaired especially with static AFOs; the time spent walking 10 metres with these orthoses increased by 172% with respect to barefoot; less difference (113%) has been reported wearing dynamic AFOs.

CONCLUSION

Static and dynamic AFOs improved static balance, while dynamic balance was impaired especially by static AFOs; less negative influence on dynamic balance has been found while wearing dynamic AFOs.

Possible interchromosomal effect in embryos generated by gametes from translocation carriers

BACKGROUND

The incidence of abnormal pregnancies in carriers of balanced translocations depends strictly on the chromosomes involved in the translocations. The aim of this study was to verify whether conventional aneuploidy screening could be advantageously combined with preimplantation genetic diagnosis (PGD) for translocations.

METHODS

Twenty-eight carriers of Robertsonian and reciprocal translocations underwent 43 PGD cycles; specific probes were used to screen the translocation in 172 embryos generated by 35 cycles; most of these embryos were also screened for chromosomes 13, 16, 18, 21, 22 (n = 166), XY (n = 107), 1 (n = 17) and 15 (n = 88). For the remaining eight cycles (carriers of reciprocal translocations) only the chromosomes involved in common aneuploidy screening were investigated on the 40 embryos generated in vitro.

RESULTS

In Robertsonian translocations, the proportion of embryos with abnormalities due to the translocation was 21%, common aneuploidies contributed 31% of total abnormalities, whereas the remaining 36% of embryos had abnormalities due to both types of chromosome. For reciprocal translocations, the chromosomes involved in the translocation were responsible for 65% of total abnormalities; only 6% of the embryos were abnormal for common aneuploidies and 16% carried abnormalities due to both the chromosomes involved in the translocation and those not related to the translocation.

CONCLUSIONS

An interchromosomal effect seems to play a role in the case of Robertsonian translocations, where the relevant contribution of aneuploidy exposes the couple to an additional risk of abnormal pregnancy.

Nonpeptidomimetic farnesyltransferase inhibitor RPR-115135 increases cytotoxicity of 5-fluorouracil: role of p53

A new nonpeptidic farnesyltransferase inhibitor, RPR-115135, in combination with 5-fluorouracil (5-FU) was studied in an isogenic cell line model system consisting of human colon cancer HCT-116 cells. HCT-116 cells were transfected with an empty control pCMV vector and with a dominant-negative mutated p53 transgene (248R/W). We found that, relative to control transfectants, there was a slight tendency for the p53 inactivated cells to be less sensitive to 5-FU after 6 days of continuous treatment. Simultaneous administration of RPR-115135 and 5-FU, at equitoxic concentrations, resulted in an enhancement of 5-FU cytotoxicity, especially in the CMV-2 clone. Growth inhibition could be accounted for on the basis of a specific cell cycle arrest phenotype (G(2)-M arrest in CMV-2 and S arrest in mutated clones), as assayed by flow cytometry. The combination RPR-115135 + 5-FU increases apoptotic events only in the CMV-2 clone.

Induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor RPR-115135: role of gene mutations

To investigate the relationship between oncogene activation and induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor, RPR-115135, two isogenic cell lines, human colon cancer line HCT-116, which harbors a K-ras mutation, and spontaneously immortalized human breast epithelial cell line MCF-10A, were utilized. HCT-116 cells were transfected with an empty control pCMV vector (clone CMV-2) or with a dominant negative mutated p53 transgene (clone Mu-p53-2) to disrupt p53 function. In both clones RPR-115135 induced a significant increase in the frequency of micronucleation at concentrations that did not affect cell membrane integrity. RPR-115135 produced a significant increase in the ratio of CREST+ to CREST- micronuclei. MCF-10A cells were stably transfected with either c-Ha-ras or c-erbB-2 or both H-ras + c-erbB-2. No induction of micronuclei was observed. No induction of micronuclei was reported in human lymphocytes and in primary spinal cells obtained from 7-day chick embryos. In conclusion, RPR-115135 acts as an aneugenic agent in a complex manner, dependent upon the complement of mutations in cell regulatory genes in tumour cells and this activity may be independent of ras genotype.

RPR-115135, a new non peptidomimetic farnesyltransferase inhibitor, induces G0/G1 arrest only in serum starved cells

A new non peptidomimetic farnesyltransferase inhibitor, RPR-115135, was studied in an isogenic cell model system consisting of human colon cancer HCT-116 line. HCT-116 cells were transfected with an empty control pCMV vector or with a dominant-negative mutated p53 transgene to disrupt p53 function. Growth inhibitory effects of RPR-115135 were evaluated on cells growing under different conditions (serum starvation, serum starvation and recovery, nocodazole treatment). The cytotoxic activity of RPR-115135 was independent of the cell cycle status of the target cells. Addition of RPR-115135 only to cells exposed to reduced serum conditions (0.1% FCS) resulted in an enhanced ability of HCT-116 cells to arrest in the G0/G1 phase. This arrest response appeared independent of p53/p21cip1/waf-1 function. A reduction of Cyclin A protein amount by RPR-115135 was observed in both clones. These latter results suggest that RPR-115135 might down-regulate the cell cycle factor that would normally impede G0/G1 arrest.

[Rheologic modifications induced by heparin therapy. Capillary blood viscosity, erythrocyte deformability, aggregation index]

BACKGROUND

The most important problem with which doctors have to deal every day in their practice, is occlusive vascular disease, at the basis of which there is commonly a process of thrombosis. For this reason, it is very important to define early the subjects at thrombosis risk and an appropriate therapeutic strategy.

METHODS

We considered 13 inpatients at thrombosis risk, c/o sezione di Clinica Medica I, dipartimento di Medicina Interna e Terapia Medica, Università di Pavia, IRCCS Policlinico S. Matteo, and 12 healthy volunteers, between March and June 1998, evaluating age, sex, weight, diseases and ongoing therapy, hemocytological, hemocoagulational and hemorheological tests before and after heparinic therapy.

RESULTS

General blood viscosity, measured by the rotational and double-filtration method, presented no significant changes; on the contrary, capillary blood viscosity and erythrocyte deformability, measured by our new double-filtration method, showed respectively an increase and a decrease.

CONCLUSIONS

Calcium heparin is the most frequently used antithrombotic drug in thrombotic diseases and their prevention, but its action on the hemorheological profile is not clear. This study showed that it increases erythrocyte aggregation rate and decreases erythrocyte deformability, having a negative effect on the microcirculation.