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C D Fegan

Publications and source records attributed to C D Fegan.

29 records · Page 2Linked to original sources
PubMed1998

Circulating CD34+ counts and apheresis planning.

The success of peripheral blood progenitor cell (PBPC) transplantation depends upon harvesting adequate numbers of cells and accurate prediction of when to commence apheresis. Although peripheral white cell count (WBC) is commonly used to identify when to initiate apheresis it does not uniformly predict the CD34+ content of the apheresis product nor the number of exchange procedures required. We investigated whether the peripheral blood CD34+ count would not only predict harvest yield but whether it would also predict the number of apheresis procedures needed to generate at least 2 x 10(6)/kg CD34+ cells. CD34+ counts were performed over an 8-month period on the peripheral blood and PBPC harvests of all patients undergoing leucopheresis. Regression analysis showed a highly significant correlation between peripheral blood CD34+ count and yield of CD34+ cells in the apheresis product. The regression plot with WBC was weaker. We have shown that a peripheral CD34+ count > or = 62 x 10(6)/l is required to confidently achieve an adequate harvest in one apheresis, two aphereses are needed if the initial count is > or = 40 x 10(6)/l. Therefore peripheral blood CD34+ counts not only are able to determine the threshold at which to commence apheresis but are useful in predicting apheresis requirements and planning demands on the apheresis service.

Adult↗
PubMed1998

Trisomy 12 is seen within a specific subtype of B-cell chronic lymphoproliferative disease affecting the peripheral blood/bone marrow and co-segregates with elevated expression of CD11a.

In order to delineate the specific morphological and immunophenotypic features of B-cell lymphoproliferative disorders associated with trisomy 12, 172 sequential unselected cases of CD19+CD5+ B-cell disorders, primarily affecting the peripheral blood and bone marrow, were studied. Trisomy 12 was found in 24 cases (13.9%), with all cases morphologically classified as either CLL-PL or CLL-mixed by FAB criteria. Trisomy 12 was not found in any cases of typical CLL. Trisomy 12 cases demonstrated a significant higher expression of CD11a (P<0.0001) and CD20 (P<0.0006) when compared to cases with the equivalent morphology and immunophenotype, but without the chromosomal abnormality. Trisomy 12 cases also demonstrated a higher frequency of FMC7, CD38 expression and moderate to strong surface immunoglobulin staining. However, no correlation was detected between the percentages of trisomy 12 cells and cells expressing CD11a, CD38, FMC7 or sIg mean fluorescent intensity. Cells from trisomy 12 positive cases were sorted according to their CD11a expression using fluorescent activated cell sorting. There was a significant increase in the percentage of trisomy 12 cells within the CD11a+ sorted fraction compared to the unsorted population (P < 0.05), implying that trisomy 12 is associated with increased expression of CD11a. With the highly specific morphological and immunophenotypic features demonstrated by trisomy 12 cases in this study, it is highly likely that these cases constitute a specific group of B-cell lymphoproliferative disorders.

Adult↗
PubMed1998

Tinzaparin as an antithrombotic: an overview.

Tinzaparin is a low molecular weight heparin which is given subcutaneously once daily without the need for laboratory monitoring. Already established as effective therapy for deep venous thrombosis, in November 1997 it became the first low molecular weight heparin to be licensed for the treatment of pulmonary embolism.

Fibrinolytic Agents↗
PubMed1997

Deletions at 11q identify a subset of patients with typical CLL who show consistent disease progression and reduced survival.

Eighty-four patients with typical chronic lymphocytic leukemia (CLL) (by morphological and immunophenotypic criteria) on whom karyotypes were available were studied. Binet stage at diagnosis and follow-up were defined. Survival was calculated from diagnosis. Fifty-one percent of patients had a karyotypic abnormality, the commonest being abnormalities at 13q14 (16%); these patients did not have significantly different survival from patients with normal karyotype. The second commonest abnormality was del(11q) (13%); these patients had significantly worse survival when compared both with patients with normal karyotype (P < 0.0001) and with other patients with karyotypic abnormality (P = 0.0012). All patients with del(11q) had progressed to stage C at follow-up while only 20% of the other patients had shown any disease progression (P < 0.0001). Del(11q) may identify a subset of patients with typical CLL who have worse survival and consistent disease progression and in future may help define a group of patients with CLL who could benefit from earlier or more intensive therapy.

Adult↗
PubMed1995

C-myc amplification, double minutes and homogenous staining regions in a case of AML.

c-myc amplification is usually associated with lymphoid malignancies and Burkitt's lymphoma in particular. We present a case of AML with c-myc amplification which was associated with homogenous staining regions (hsr) and double minutes (dmin). The administration of GCSF following induction chemotherapy resulted in a marked increase in blast numbers. The GCSF was stopped and further courses of chemotherapy given, which resulted in complete remission. The patient relapsed 7 months after diagnosis and failed to go into a second remission with reinduction therapy. We conclude that c-myc amplification is a rare event in AML, but may be associated with chemotherapy resistance and a poor prognosis, are as dmins and hsr. Growth factors should be used with caution in these patients.

Aged↗
PubMed1995

Serum erythropoietin during autologous bone marrow transplantation: relationship to measures of erythroid activity.

Marked elevation of serum erythropoietin (sEPO) occurs following high dose chemotherapy for malignant disease. It has been proposed that the subsequent fall in sEPO constitutes a relative erythropoietin (EPO) deficiency, prompting trials of recombinant EPO to reduce red cell transfusion during chemotherapy. We have investigated these phenomena by serial estimations of reticulocytes and sEPO in 11 autologous marrow transplant recipients. sEPO reached two to five times baseline 0 to 5 days after transplant but the inverse relationship between sEPO and haematocrit was maintained. Observed to expected log sEPO (Epo ratio) rose and fell in parallel with sEPO, remaining greater than 1.0 throughout. A progressive fall in reticulocyte count during chemotherapy was followed by an increase during engraftment. The strong inverse relationships between reticulocytes and Epo ratio in the 10 days after initiating chemotherapy support the hypothesis that loss of EPO-receptor bearing erythroid precursors allows a rise in sEPO during chemotherapy. The elevation of Epo ratio levels during engraftment indicates that it is the availability of EPO-sensitive progenitors, rather than the supply of EPO, that limits the rate of resumption of erythropoiesis after high-dose chemotherapy.

Adult↗
PubMed1992

Evaluation of erythropoiesis after bone marrow transplantation: quantitative reticulocyte counting.

Erythroid regeneration is an important and separate element in the engraftment process in allogeneic and autologous bone marrow transplantation (alloBMT, autoBMT). Qualitative visual reticulocyte counting has proved inadequate in the evaluation of erythropoiesis after BMT but automated flow cytometry now allows the reliable quantitation of reticulocytes even to very low levels. Reticulocyte counts and highly fluorescent reticulocyte (HFR) counts (very early reticulocytes) were estimated daily in recipients of 22 autoBMT and 14 alloBMT using a Sysmex R-1000 automated reticulocyte counter. Marrow ablation caused an immediate and rapid fall in both the reticulocyte count and the HFR. Measurable numbers of reticulocytes persisted throughout the hypoplastic period, but HFR fell to zero in the majority of both the autoBMT and alloBMT. HFR rose significantly after a median time of 14 d post-autoBMT, and 12 d post-alloBMT. Attainment of 15 x 10(9)/l reticulocytes and 0.5 x 10(9)/l HFR at day 21 post-transplant was associated with ultimate engraftment in 100% cases. Inadequate engraftment was seen in the majority of patients whose responses fell below these levels. Graft-versus-host disease was associated with a transient slight reduction in reticulocyte count. Neither episodes of infection nor blood transfusions had any significant impact on trends of reticulocytes or HFR. Automated flow cytometric reticulocyte counting has been shown to provide an accessible measure of erythroid activity which may be of predictive value in the management of patients following bone marrow transplantation.

Blood Cell Count↗