Flow cytometric enumeration of CD34+ hematopoietic stem and progenitor cells in leukapheresis product and bone marrow for clinical transplantation: a comparison of three methods.

Flow cytometric enumeration of CD34+ hematopoietic stem and progenitor cells (HSCs) is widely used for evaluation of graft adequacy of peripheral blood and bone marrow stem cell grafts. In the present study, we review and compare the major counting techniques of stem and progenitor cells. The methods are: the Milan/Mullhouse protocol, two-platform ISHAGE (International Society of Hematotherapy and Graft Engineering) and single-platform ISHAGE analysis system. According to the Milan/Mulhouse protocol, HSCs are identified by CD34 antibody staining and easy gating strategy. The ISHAGE guidelines for detection of CD34+ cells are based on a four-parameter flow cytometry method (CD34PE/CD45PerCP staining, side and forward angle light scatter) thus employing multiparameter gating strategy. With two-platform ISHAGE protocol, an absolute CD34+ count is generated by incorporating the leukocyte count from an automated hematology analyser. The single-platform ISHAGE method to determine the absolute CD34+ count directly from a flow cytometer includes the use of Trucount tubes (Becton Dickinson) with a known number of fluorescent beads. CD34+ cells were quantified in mobilized peripheral blood, collected by leukapheresis, and bone marrow from 42 samples from patients with hematological malignancies. The differences against the means display low disagreement between the Milan/Mulhouse and ISHAGE protocols, with discrepancies of up to 2.5% (two-platform ISHAGE)--2.6% (single-platform ISHAGE) in enumeration of CD34+ cells in leukapheresis product and 4.8% (two-platform ISHAGE)--4.9% (single-platform ISHAGE) in bone marrow. Our results show high correlation among all three methods. Since the three protocols are compatible, choosing the most convenient in terms of costs, simplicity and compliance with clinical results appears to be a logical consequence

61. The outcomes of the conventionally fractionated radiotherapy in the prospectiive and retrosprctive studies. Is the meaning of conventionality the same?

AimTo discuss some problems of the “conventionality” in the prospective and retrospective studies finished last year at the RT Department in Warsaw. The phase III clinical trial. The study was conducted according to the evidence based rules. Cancer of the larynx – glottis and supragiottis T1 – T3 NO M0 WHO 0 – 1, 395 cases 196 in experimental, 199 in conventional arm. The retrospective study concerned all patients with the cancer of larynx treated radically in the II department in years 1989 to May 1995. 372 patients T1- T4, N1-N3, M0. The prospective material 150 patients were selected [age 75 and less, WHO 0–1, T1–T3, NO, M0] employing the same selection criteria as in the prospective study. The comparison was performed with the conventional arm of the clinical trial [199 cases].Results of the studySignificant differences were recorded in the: ? performance status and in the number of T1 and T3 cases, ? compliance to protocol in the total dose and the overall treatment time, ? response to treatment in the whole group and in the particular stages These results indicate the very demanding selection of cases and much more rigorous compliance with the therapeutic protocol in the prospective study. The response to treatment was about 20% higher in the clinical trial group. The 20% difference between the outcomes in the prospective and retrospective studies recorded in the response to treatment was similar in the 1, 2, and 3 years local control observations

Leadership training to improve adenoma detection rate in screening colonoscopy: A randomised trial

Objective Suboptimal adenoma detection rate (ADR) at colonoscopy is associated with increased risk of interval colorectal cancer. It is uncertain how ADR might be improved. We compared t

Spontaneous apoptosis in ovarian carcinomas: a positive association with p53 gene mutation is dependent on growth fraction

Changes in cell survival contribute to tumour development, influence tumour biology and its response to chemotherapy. p53 gene alterations should negatively affect apoptosis by impaired p53-dependent apoptotic response. We looked for associations between spontaneous apoptosis, p53 gene mutation, p53 protein accumulation, growth fraction, bcl-2 expression and histological parameters in 64 ovarian, four tubal and three peritoneal carcinomas. Apoptotic cells were detected with the TUNEL method. p53 gene variants were detected by the single-strand conformation polymorphism and were sequenced directly. P53, Ki-67 and bcl-2 protein expressions were detected immunohistochemically. A weighed multiple logistic regression model was applied. Apoptotic index (Al) ranged 0.02–0.18 (mean 0.11); proliferation index (PI) ranged 3–90% (mean 54%). p53 gene mutations were present in 51, p53 protein accumulation in 46, and diffuse bcl-2 expression in 29 of 71 tumours. The AI was positively associated with the presence of p53 gene mutation (P = 0.011). However, the PI included into the analysis did positively influence the AI (P = 0.02) and diminished the association with p53 gene mutation (P = 0.082). The AI was negatively associated with good histological differentiation (P = 0.0006), the serous tumour type (P = 0.002), and diffuse bcl-2 expression (P = 0.025). Strong bcl-2 expression was associated with endometrioid tumour type (P = 0.002). FIGO stage and p53 protein accumulation were the only parameters that influenced overall survival time. Thus, our results suggest that histological tumour type and grade are major determinants of spontaneous apoptosis in ovarian carcinomas;p53 alterations do not adversely but rather positively affect spontaneous apoptosis by increasing growth fraction. This, in turn, suggests p53-independency of spontaneous apoptosis in ovarian carcinomas. © 2000 Cancer Research Campaig

tRNA structural and functional changes induced by oxidative stress

Oxidatively damaged biomolecules impair cellular functions and contribute to the pathology of a variety of diseases. RNA is also attacked by reactive oxygen species, and oxidized RNA is increasingly recognized as an important contributor to neurodegenerative complications in humans. Recently, evidence has accumulated supporting the notion that tRNA is involved in cellular responses to various stress conditions. This review focuses on the intriguing consequences of oxidative modification of tRNA at the structural and functional level

TP53 status and taxane-platinum versus platinum-based therapy in ovarian cancer patients: A non-randomized retrospective study

<p>Abstract</p> <p>Background</p> <p>Taxane-platinum therapy (TP) has replaced platinum-based therapy (PC or PAC, DNA damaging chemotherapy) in the postoperative treatment of ovarian cancer patients; however, it is not always effective. TP53 protein plays a differential role in response to DNA-damaging agents and taxanes. We sought to define profiles of patients who benefit the most from TP and also of those who can be treated with PC.</p> <p>Methods</p> <p>We compared the effectiveness of PC/PAC (n = 253) and TP (n = 199) with respect to tumor TP53 accumulation in ovarian cancer patients with FIGO stage IIB-IV disease; this was a non-randomized retrospective study. Immunohistochemical analysis was performed on 452 archival tumors; univariate and multivariate analysis by the Cox's and logistic regression models was performed in all patients and in subgroups with [TP53(+)] and without TP53 accumulation [TP53(-)].</p> <p>Results</p> <p>The advantage of taxane-platinum therapy over platinum-based therapy was seen in the TP53(+), and not in the TP53(-) group. In the TP53(+) group taxane-platinum therapy enhanced the probability of complete remission (p = .018), platinum sensitivity (p = .014), platinum highly sensitive response (p = .038) and longer survival (OS, p = .008). Poor tumor differentiation diminished the advantage from taxane-platinum therapy in the TP53(+) group. In the TP53(-) group PC/PAC was at least equally efficient as taxane-platinum therapy and it enhanced the chance of platinum highly sensitive response (p = .010). However, in the TP53(-) group taxane-platinum therapy possibly diminished the risk of death in patients over 53 yrs (p = .077). Among factors that positively interacted with taxane-platinum therapy in some analyses were endometrioid and clear cell type, FIGO III stage, bulky residual tumor, more advanced age of patient and moderate tumor differentiation.</p> <p>Conclusion</p> <p>Our results suggest that taxane-platinum therapy is particularly justified in patients with TP53(+) tumors or older than 53 years. In the group of patients ≤53 yrs and with TP53(-) tumors platinum-based therapy is possibly equally efficient. We provide hints for planning randomized trials to verify these observations.</p