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Biomedical subjects

D W Ross

Publications and source records attributed to D W Ross.

At least 55 records · Page 3Linked to original sources
PubMed1989

Flow cytometric correlation of the c-myc oncoprotein and cell cycle kinetics of HL60 leukaemia during induced maturation with cytosine arabinoside and dimethylsulphoxide.

The c-myc oncogene codes for a DNA binding protein that functions in a cell cycle-related manner. A useful model for studying the relationship of c-myc expression with cell cycle kinetics is the HL60 cell line. HL60 cells constitutively express high levels of c-myc mRNA; however, the level can be down-regulated as the cells are induced to differentiate. We have developed a flow cytometric assay for correlating c-myc oncoprotein levels with DNA content. C-myc oncoprotein levels were additionally correlated with c-myc mRNA levels as determined by slot blot hybridization. Dimethylsulphoxide (DMSO) and cytosine arabinoside were used to induce granulocytic and monocytic maturation respectively. Treatment of HL60 cells with DMSO leads to an increase in the per cent of cells in G1/G0 and a decrease in mean c-myc mRNA and oncoprotein levels. The cells with G1 DNA content show the greatest decrease in c-myc protein. ARA-c treatment of HL60 cells leads to a slowing and an accumulation of cells in S phase with a moderate decrease in mean mRNA and only a slight decrease in mean c-myc protein levels. These data support the hypothesis that c-myc is involved in the switch from G1 to G0.

Blotting, Northern↗
PubMed1989

Juvenile chronic myeloid leukemia: oncogene characterization.

A 31/2-year-old female presented with thrombocytopenia and anemia. The bone marrow showed marked hemophagocytosis with an increase in macrophages. Over the next 2 months, there was a progressive de-differentiation of this monocytic population with the accumulation of blasts in the blood and bone marrow. The blasts had a normal 46XX karyotype and showed no fusion of the bcr and abl genes associated with Philadelphia chromosome positive leukemia. Intensive chemotherapy produced a transient hypoplastic state during which a bone marrow transplant was performed. The bone marrow after transplant again demonstrated a large population of macrophages. These cells continued to de-differentiate over the ensuing year up until the time of the patient's death. The mononuclear blast cell population was inducible toward monocytic maturation in tissue culture by low doses of ARA-c or daunorubicin. These mononuclear blasts expressed c-myc and c-fos mRNA at high levels, a further marker of their proliferative state and monocytic origin.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

The clinical utility of discriminant functions for the differential diagnosis of microcytic anemias.

Several groups of authors have derived discriminant functions (DFs) based on red cell indices (primarily MCH, MCV, and RDW) that can be used to differentiate iron deficiency from thalassemia minor. The Technicon H*1 analyzer provides a direct MCHC measurement (termed the CHCM), in addition to the conventional computed value (Hgb/PCV). To evaluate the clinical utility of red cell discriminant analysis, chart review was performed in 176 cases for which hemoglobin characterization and quantitation studies had been requested. Six published discriminants were evaluated for cases of clearly defined iron deficiency anemia and thalassemia minor. Overall diagnostic efficiency ranged from 50%-82%, and the diagnostic performance of three of the discriminants failed to achieve statistical significance. Mean values for both MCHC and CHCM were significantly lower in patients with iron deficiency than in patients with other causes of microcytic anemia. It was also observed that MCHC was significantly greater than CHCM in patients with iron deficiency anemia, but not in patients with other causes of microcytic anemia. Both MCHC and the difference between MCHC and CHCM showed potential value as parameters for the differential diagnosis of iron deficiency from other causes of microcytic anemia. It was noted, however, that in 67% of the cases studied, the use of a DF could not have resolved the diagnosis to the extent that hemoglobin characterization and quantitation studies were no longer indicated.

Anemia, Hypochromic↗
PubMed1988

Stability of hematologic parameters in healthy subjects. Intraindividual versus interindividual variation.

An automated complete blood count with white blood cell differential was performed yearly on successive groups of healthy second-year medical students from 1979 through 1987. For three classes (1984-1987), the counts were repeated on the same people nine months later. These data demonstrated that the mean value of all hematologic parameters was quite stable over nine years. This allowed for an estimation of the upper limit for the combined effects of drift in accuracy, precision, and biologic stability. The stability was achievable despite an evolution in technology and quality assurance methods over that period. A comparison of intraindividual versus interindividual variation demonstrated that a normal range based on population statistics may be less sensitive than a normal range established for a person during routine health maintenance, especially for the platelet count.

Adult↗
PubMed1988

Leukemic cell maturation: phenotypic variability and oncogene expression in HL60 cells: a review.

Leukemic cells in vitro and in vivo demonstrate an unstable phenotype. We have observed in HL60 cells maintained in culture over long periods of time such phenomena as emergence of drug resistance, oncogene amplification, loss of granulocyte and monocyte lineage markers, and alteration in cell growth parameters. As summarized in this report, a comprehensive review of the literature on HL60 cells shows a wide diversity of phenotype for these cells. We have developed and acquired from other laboratories a series of HL60 sublines with varying phenotypic characteristics. The time in continuous log phase culture for HL60 cells (passage 13 ATCC, Rockville MD) to undergo phenotypic drift from a heavily granulated promyelocytic cell to a more undifferentiated agranular blast form on four occasions varied from 3 to 18 months. The actual loss of promyelocytic phenotype occurred rapidly (within less than 1 month) following a variable period of apparent stable phenotype, The change in morphology was invariably accompanied by decreased sensitivity to ARA-c (5- to 20-fold increase in LD50 and dose necessary to induce NSE positive cells). The c-myc gene is variably amplified in sublines of HL60 cells. The expression of c-myc primarily reflects alterations in cell cycle kinetics and was not found to be correlated with a switch between proliferation and maturation. These results suggest that phenotypic drift may be due to loss of response to regulatory signals that affect the expression of a number of cellular genes.

Cell Differentiation↗
PubMed1987

Diagnosis of infective and inflammatory disorders by flow cytometric analysis of blood neutrophils.

The utility of neutrophil parameters provided by two flow cytometric hematologic analyzers (the H-1 and H6000, Technicon Instruments Corporation, Tarrytown, NY) was investigated for the diagnosis of infective and/or inflammatory disorders. The test population of 156 hospital patients was selected on the basis of a blood culture request. Positivity or negativity for infective and/or inflammatory disease was inferred from chart review. The parameters evaluated included the absolute neutrophil count, the lobularity index, and the left shift flag from the H-1, the percentage of high peroxidase cells from the H6000, the routine laboratory band count, and a reference band count. Significant intercorrelations were observed between these parameters. The diagnostic performance of the routine laboratory band count was significantly inferior to that of all other parameters. At equivalent points on their receiver operating characteristic curves, the diagnostic efficiencies of the remaining tests ranged from 61.5% for the lobularity index to 67% for the left shift flag and the percentage of high peroxidase cells. These differences were not significant statistically.

Flow Cytometry↗
PubMed1986

Measurement of myeloid maturation by flow cytochemistry in HL-60 leukemia: esterase is inducible, myeloperoxidase is not.

The phenomenon of leukemic cell maturation requires a measurement of myeloid maturation to understand the process and to exploit it as a means of therapy for leukemia. The HL-60 leukemic cell line was used as a model of induced leukemic cell maturation in order to develop a method of quantitating granulocytic and monocytic maturation in response to drug therapy. An automated flow cytochemistry system (Hemalog-D) was employed to measure mean cell volume, myeloperoxidase (MPO), and nonspecific esterase (NSE). For granulocytic maturation induced by vitamin A or DMSO, MPO and cell volume decreased by 50%, maintaining a constant mean cellular MPO concentration throughout maturation from promyelocyte to neutrophil-like forms. For monocytic maturation induced by low-dose ARA-c, the mean NSE increased substantially, while cell volume remained constant. Unlike MPO concentration, NSE was truly inducible and thus a useful quantitative measure of maturation caused by low-dose ARA-c. Flow cytochemistry and cytofluorometry may be developed to allow for quantitative monitoring of therapeutic trials of induced maturation in human leukemias. However, this will require adapting these techniques to the complexity of human leukemias in vivo, and the necessity of handling heterogeneous populations encountered in bone marrow samples.

Cell Line↗
PubMed1986

Evaluation of an automated hematology system (Technicon H-1).

We evaluated the Technicon H-1 hematology system, a new third-generation blood cell analyzer that performs a complete blood cell count, including red blood cell (RBC) morphometric studies and a full white blood cell differential count. Linearity and precision were acceptable over the entire clinical range. We compared the H-1 with the Technicon H-6000 and the Coulter S Plus IV. Close correlation was observed for all equivalent parameters except the mean corpuscular hemoglobin concentration (MCHC), the mean platelet volume, and the basophil count. Poor correlation for the MCHC reflects the novel methodology of the H-1 for measuring RBC size and, independently, RBC hemoglobin content. The H-1 MCHC correlates with hypochromia as assessed morphologically, while the MCHC of the H-6000 or S Plus IV does not. Further technological innovations include measurement of the mean neutrophil peroxidase content and nuclear lobularity.

Blood Cell Count↗
PubMed1986

Leukemic cell maturation: variability of the myeloid leukemic cell phenotype.

Leukemia is characterized by a proliferation of cells that exhibit an arrest in the normal differentiation sequence. The HL-60 promyelocytic leukemia is a useful model of the phenomenon of maturation arrest, particularly as modulated by inducers that partially restore myeloid differentiation. In this investigation, we report the development of two sublines of HL-60 and the acquisition of two others that are clonal variants of the parent cell line. Each of the sublines demonstrates an altered pattern of differentiation and resistance to one or more of the drugs that serves as an inducer of the parent line. The two cell lines developed in this study, HL-60S and HL-60I, are resistant to arabinosylcytocine (ARA-c); HL-60I is also resistant to PMA. A study of the phenotype as expressed by the granule-associated cytoplasmic enzymes revealed that each subline had a slightly different pattern of maturation in response to dimethylsulfoxide (DMSO) or ARA-c as inducers. The proliferative rate of all sublines was similar. These data demonstrate that the maturation arrest observed in this model is in part reversible. The maturation arrest observed in myeloid leukemias is due to a reversible block secondary to altered proliferative activity.

Butyrates↗
PubMed1985

Evaluation of the Coulter three-part differential screen.

An evaluation of the Coulter Electronics, Inc. (Hialeah, FL) three-part differential screen (3PD) was undertaken to determine the performance characteristics of this system. The 3PD measures white blood cell (WBC) volumes and, by automatic analysis of the resultant WBC histogram, produces a determination of the number and percent of lymphocytes, mononuclear cells, and granulocytes. A group of 984 random patient blood samples was tested. The overall review rate (samples requiring some further analysis or review) was 42%. The main source of false negatives on the 3PD was eosinophilia: 5 out of 22 instances of eosinophilia greater than 750/microL were not flagged. The precision of the three parameters, measured as percent coefficient of variation, was 3.3% for lymphocytes, 14.2% for mononuclear cells, 3.1% for granulocytes, and 2.4% for the total WBC. The stability of blood samples was acceptable for up to eight hours at room temperature (less at 4 degrees C).

Eosinophils↗
PubMed1985

Peritoneovenous shunting for cirrhotic versus malignant ascites.

The use of the peritoneovenous shunt in patients with cirrhosis is associated with a significantly higher complication rate than in patients with malignant ascites. Since many patients subsequently died due to the complications of shunt placement and the efficacy has never been clearly established by a randomized trial, it is difficult to recommend a procedure which may shorten the already brief life expectancy of the patient. We conclude that for the patients with ascites due to cirrhosis, the peritoneovenous shunt should be reserved for a carefully selected group, such as those patients with pending rupture of a hernia. However, for the patient with malignant ascites, the relatively low complication rate of peritoneovenous shunt placement and the lack of an adverse effect on survival time indicates that use of this successful palliative technique seems warranted in selected patients.

Adult↗
PubMed1985

Myeloperoxidase deficiency. Increased sensitivity for immunocytochemical compared to cytochemical detection of enzyme.

The discovery of hereditary deficiency of myeloperoxidase (MPO) in neutrophils and monocytes of affected individuals has been based on the absence of cytochemical staining in these peripheral blood cells. We report that an immunocytochemical method shows more sensitivity than either the benzidine or 4-chloro-1-naphthol cytochemical methods. In MPO-deficient subjects, immunocytochemistry detects a marked decrease, but not absence, of MPO.

Benzidines↗
PubMed1985

Differences in cell cycle kinetics during induced granulocytic versus monocytic maturation of HL-60 leukemia cells.

Leukemia cells (HL-60) were induced to mature towards granulocytic and monocytic phenotypes using 1.1% dimethyl sulfoxide and 5 X 10(-7) M 1-beta-D-arabinofuranosylcytosine, respectively. Granulocytic maturation was accompanied by a slight decrease in cell volume and in total cell protein, but with an increase in acid phosphatase. DNA histograms showed that after 7 days there was a decrease in the number of cells with S or G2 DNA content. Autoradiography revealed that most of the cells had stopped in cycle with only 3% of the cells synthesizing DNA. The rate of synthesis for these few cells, morphologically identified as immature blast forms, was not diminished. Monocytic maturation was accompanied by an increase in cell volume and of alpha-naphthyl acetate esterase. DNA histograms showed no change over 7 days. Autoradiography revealed a large fraction of the cells to be in cycle and synthesizing DNA, but at a markedly reduced rate. Induced granulocytic and monocytic maturation are characterized by a very different perturbation of the cell DNA-division cycle.

Cell Count↗
PubMed1985

Leukemic cell maturation.

Leukemic blasts can be induced by external chemical agents to mature to neutrophils, monocytes, or RBCs. The phenotype of leukemic cells thus results from both internal genetic aberrations and the response of leukemic cells to their external environment. When human myeloid leukemia cells are exposed in vitro to a variety of agents (eg, vitamin A or dimethyl sulfoxide) the blasts lose their proliferative potential, the expression of oncogene products is sharply decreased, and after five days the leukemic cells become morphologically mature and functional neutrophils. Some patients with myeloid leukemias have responded to therapy designed to induce maturation in vivo. The induced maturation of leukemic cells is a new therapeutic tactic--an alternative to cytotoxic drug therapy--wherein leukemic cells are destroyed by transforming them into neutrophils.

Cell Differentiation↗
PubMed1985

Viscous factors in peripheral tissue perfusion.

To ascertain the relative importance of the factors that influence blood viscosity (VIS), we measured hematocrit (HCT), filterability index, fibrinogen level (FIB), and Ektacytometer indices at osmolarities of both 290 (EI 290) and 200 (EI 200) in 21 diabetic patients with peripheral vascular disease (DPVDs) and 11 healthy volunteers (HVs). Stepwise multiple regression analyses generated a formula based on three of the independent variables (FIB, HCT, EI 200) that accurately predicted VIS (r = 0.79, p less than 0.01). Based on the beta coefficients and F statistics, HCT and FIB were the most important elements in the linear regression equation. Compared with HVs the total group of DPVDs had lower HCT (36.5% vs. 42.4%) and higher FIB (661 vs. 276 mg/dl, p less than 0.01) values. When all HVs were compared with a subgroup of DPVDs with similar HCT (n = 10), both FIB and VIS were higher (p less than 0.001) in the DPVD than in the HV group. We conclude that the most important of the multiple factors that influence VIS are HCT and FIB. The finding of increased FIB in DPVDs could have important implications for drug and surgical therapy in this group of patients.

Blood Circulation↗
PubMed1985

Transient granulocyte maturation arrest: discovery by flow cytometry of a variant form of agranulocytosis.

A 5-year-old child presented with pneumonia and agranulocytosis. A Wright-stained peripheral blood smear showed only cells which had the morphological appearance of lymphocytes, plus a few monocytes and eosinophils. A bone marrow aspirate smear showed a complete lack of recognizable granulocyte precursors. However, the admission CBC and differential performed by automated flow cytochemistry (Technicon Instruments Corporation H-6000) measured 32% granulocytes as determined by peroxidase activity. Cytochemical stains on the blood and marrow smears revealed that many of the cells that had the morphological appearance of lymphocytes were positive for myeloperoxidase activity. Special studies on these cells revealed them to be abnormal, intermediate granulocytes with azurophilic, peroxidase-containing primary granules, but with few secondary granules and limited lactoferrin activity. Over 28 days the child recovered, first with granulocytic hyperplasia in the marrow and then a return of the peripheral blood to normal. This is the first case report of an episode of transient "agranulocytosis" which in reality was a maturation arrest.

Agranulocytosis↗