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Biomedical subjects

G Mango

Publications and source records attributed to G Mango.

At least 19 recordsLinked to original sources

Automated measurement of red blood cell microcytosis and hypochromia in iron deficiency and beta-thalassemia trait.

Some routine red blood cell (RBC) measurements and indexes (count, mean volume, volume dispersion, and mean hemoglobin [HGB] concentration) can be used to differentiate iron deficiency from heterozygous beta-thalassemia. A number of formulas that incorporate two or more of these measurements have been described to amplify such differences. The H*1 hematology analyzer directly measures volume and HGB concentration of individual RBCs. We have assessed the diagnostic usefulness of conventional and new RBC measurements provided by the H*1 on a learning data set that comprised 119 patients with iron deficiency and 172 patients with beta-thalassemia trait, both untreated and uncomplicated. The most striking finding was the inverse behavior of percentages of microcytes (volume, less than 60 fL) and hypochromic RBCs (HGB concentration, less than 280 g/L) in the two conditions. In 162 of 172 patients with beta-thalassemia trait, the percentage of microcytes (mean, 33.1%; central 95th percentile range, 9.2% to 54.5%) was higher than the percentage of hypochromic RBCs (mean, 13.9%; central 95th percentile range, 1.7% to 24.7%). In 105 of 119 patients with iron deficiency, on the contrary, the percentage of hypochromic cells (mean, 34.6%; central 95th percentile range, 9.7% to 73.1%) was higher than the percentage of microcytes (mean, 12.8%; central 95th percentile range, 1.7% to 29.6%). The ratio between the percentage of microcytes and the percentage of hypochromic cells provided by the H*1 (microcytic-hypochromic ratio) was useful in differentiating the two types of microcytic anemia: with the use of a discriminant value of 0.9, the discriminant efficiency of the microcytic-hypochromic ratio was 92.4% (95% confidence interval, 88.8% to 95.2%), higher than that of the five previously described discriminant formulas and simple RBC measurements. When assessed on a test data set that comprised 149 unselected cases of microcytic anemia, a microcytic-hypochromic ratio lower than 0.9 demonstrated high sensitivity (94.0%), specificity (92.3%), and predictive value (94.0%) for the presence of iron-deficient erythropoiesis in patients with isolated iron deficiency, polycythemia vera treated by phlebotomy, and iron deficiency complicating heterozygous thalassemia. In conclusion, our results showed that iron-deficient erythropoiesis is characterized by the production of RBCs with a severely decreased HGB concentration, while microcytes of beta-thalassemia trait are generally smaller, with a more preserved HGB concentration. Such properties, as assessed by the H*1 hematology analyzer, are very useful in distinguishing these two common types of microcytic anemia.

Anemia, Hypochromic↗

Chronic myelogenous leukemia in the course of chronic lymphocytic leukemia: evidence for an independent clonal origin.

We report on a 69-year-old man who developed Ph-positive CML 6 years after the onset of B-cell CLL. When CML was diagnosed, both malignant cell populations were detected in bone marrow and peripheral blood. Peripheral leukocytes were fractionated by Ficoll-Hypaque density gradient, and cytogenetic and molecular studies were performed on mononuclear cell and granulocyte-enriched populations. Mononuclear cells were stimulated with either PHA or PWM. In PHA-treated cultures 76% of the metaphases were Ph-negative, while after PWM stimulation 87% were Ph-positive. A bcr rearrangement was observed in DNA from the granulocyte-enriched fraction, but not in mononuclear cells. On the contrary the IgH locus resulted in monoclonally rearranged DNA, only in peripheral blood mononuclear cells. These results indicate that the two neoplastic populations originated independently.

Aged↗

Analysis of leucocyte populations with the Coulter S-Plus STKR as a screening tool for haematological abnormalities.

In two institutions at Rome and Florence we evaluated the clinical sensitivity of two Coulter STKR systems using the NCCLS standard H20-T for leucocyte differential count in a patient population with high prevalence of haematologic abnormalities. Reference ranges of normal leucocytes were obtained on 278 adult subjects. On a population of 455 patient specimens, 200 specimens (44%) were flagged by the STKR because of a distributional abnormality, and 122 (27%) because of a morphological abnormality. Percentage of subtotal agreements between the STKR and the reference manual differential count was 85.4%, with 67.5% full and 20.9% partial agreements. Eight specimens that showed a morphological abnormality with the reference manual differential count were classified as normal by the STKR, with a false normal rate of 6.6%. Analysis of the STKR performance for morphological abnormalities showed acceptable sensitivity (82.0%) and rather low specificity (71.5%), low predictive value of positive results (51.3), high predictive value of negative results (91.5%) and efficiency of 74.3%. The main problems of the STKR differential count were a high rate of false monocyte count, and the misidentification of eosinophilias and low-concentration abnormal cells.

Evaluation Studies as Topic↗

Comparison of the side effects of therapeutic cytapheresis and those of other types of hemapheresis.

The side effects of a series of 2418 hemapheresis procedures performed in a total of 570 subjects (patients and donors) are described. Patients with various diseases were subjected to plasmapheresis (926 procedures in 181 patients) or cytapheresis (305 procedures in 89 patients). One hundred twelve plasmapheresis procedures and 1075 of cytaphereses were also performed in 300 blood donors. A total of 225 complications involving 107 patients (39.6%) occurred during 196 (15.9%) therapeutic procedures. Among the blood donors only 45 complications, involving 35 patients (11.6%) occurred during 45 procedures (4.2%). The complications seen with therapeutic plasmaphereses were circulatory disturbances (38% of all those observed), citrate reactions (27%), technical problems (20%), allergic reactions (9%) and miscellaneous complications (6%). Therapeutic cytaphereses were complicated by citrate reactions (44%), technical problems (25%), circulatory disturbances (14%), allergic reactions (11%) and miscellaneous complications (6%). Complications in the blood donor group included circulatory disturbances (51%), technical problems (36%) and various other problems (13%). No infectious complications or deaths were observed. The probability that adverse reactions will occur depends on the condition of the patient, the frequency of the sessions and the volume of fluid exchanged. Evaluation of the main risk factors, use of less intensive protocols and interruption of the session at the first sign of disturbances will help improve patient tolerance of these procedures.

Blood Donors↗

Semiautomated autologous bone marrow processing for transplantation.

This paper describes the development of a semiautomated procedure for autologous bone marrow processing, prior to ex vivo manipulation and/or cryopreservation. This procedure was employed with a pediatric bowl (125 ml Latham bowl) and the automated DuPont Stericell processor. We have obtained a mononuclear cell recovery of 85% and a hemopoietic progenitor cell recovery of 81% (CFU-GM; BFU-E), with a red cell removal of 84%. We believe that a reliable and standardized bone marrow processing procedure is the basic necessity for a bone marrow transplantation program.

Automation↗

Rationale for large scale bone marrow hemopoietic stem cell manipulation.

Many years have passed since the first attempt in marrow grafting was performed (1939). During this period several techniques have been developed in marrow processing and manipulation to overcome bone marrow transplant complications: the ABO barrier in case of major incompatibility between donor and recipient, the graft-versus-host disease due to the presence of allogeneic mature T-lymphocytes in cellular suspension and the neoplastic cell residue in autografts. At the end, the final volume of autologous mononuclear cell suspension must be frozen and an optimized cryopreservation allows a cell viability and subsequently an adequate medullar repopulating capacity.

Blood Group Incompatibility↗

A comparison between two different procedures for bone marrow processing: a semiautomated procedure vs manual starch sedimentation.

After high-dose chemotherapy, autologous cryopreserved bone marrow infusion is employed to restore rapidly the compromised hematopoietic function. An efficient bone marrow processing reduces the infusion toxicity produced by hemolized red cells, granulocytes and platelets clumping and DMSO amount; moreover it increases freezing efficacy, a critical step in autologous bone marrow grafting techniques. Gravity sedimentation technique with 6% hydroxyethyl-starch (HES) or a semiautomated procedure using a blood cell processor were used in our center to manipulate ex-vivo the collected bone marrow. In our experience we compared these two different procedure and we evaluated their efficiency.

Antineoplastic Combined Chemotherapy Protocols↗

Plasmapheresis in the therapy of hyperthyroidism associated with leukopenia.

Surgery, the treatment of choice for hyperthyroidism due to nodular goiter, requires an euthyroid state, which is generally achieved with thionamides. Leukopenia is the most serious toxic effect of thionamides, and it causes controindication. We report a 50-year old woman with severe hyperthyroidism and leukopenia, in whom an euthyroid state before thyroidectomy was obtained with the use of therapeutic plasmapheresis. This procedure was carried out immediately before surgery using an intermittent flow separator; three sessions removed a total of 6,300 cc of plasma. Plasmapheresis caused a rapid reduction of both total and free thyroid hormone levels. Thyroidectomy was performed without any complications. Plasmapheresis can be considered a valid and safe method to prepare hyperthyroid patients for thyroidectomy when other therapies are ineffective or counterindicated.

Antithyroid Agents↗

Oxidative stress of red blood cells stored for transfusion use.

Some oxidative indexes and the level of reduced glutathione have been determined on red blood cells stored for transfusion use. Conjugated dienes show a concentration which increases until around the third week of storage and then comes back to lower values. On the contrary malonyldialdeyde shows a decreasing level until the third week and then rises rapidly to very high values. Reduced glutathione rises until about the end of the second week and then falls to very low values. Free haemoglobin continuously rises through the whole period of storage; from these data it is evident that a storage time not exceeding 21 days gives the best transfusion results.

Alkenes↗

Myelodysplastic syndromes: analysis of 51 cases. Therapy with low doses of arabinosyl cytosine of leukaemic transformation.

Clinical, haematological, cytogenetic features and therapeutic problems of 51 patients with MDS were examined. Patients were distributed in 5 FAB subgroups: RA 21, SA 7, RAEB 8, RAEB-t 9 and MMCL 6 patients. Leukaemic transformation occurred in 3 RA, 3 RAEB, 7 RAEB-t and 3 MMCL patients. No SA patient suffered from leukaemic transformation. Cytogenetic alterations occurred in 13 of 29 examined patients; 5q- was the most common abnormality. We did not find any relation between chromosomal anomalies and FAB subgroups. Leukaemic transformation, however, was more frequent in patients with cytogenetic aberrations. In some cases it was not easy to determine the precise diagnostic allocation according to FAB subgroups; it is possible, however, to subdivide MDS prognosis into 2 classes. The more satisfactory therapy of leukaemic transformation is often due to low doses of Ara-C; this therapy allowed a better survival and sometimes to obtain CR which in a M6 ANLL patient continued for 24 months.

Aged↗

Chronic myeloid leukemia with monoclonal gammopathy terminating in myeloid crisis and immunoblastic lymphoma.

A patient, with chronic myeloid leukemia and IgA monoclonal gammopathy, who contemporaneously developed myeloid blast crisis and immunoblastic lymphoma is reported. Cytogenetic studies showed complex chromosome abnormalities concerning chromosomes 8, 14 and 22, other than the Ph chromosome. A possible relationship between the emergence of immunoblasts from slow proliferating lymphoplasmacytoid cells, myeloid blasts crisis and chromosomal changes is discussed.

Blast Crisis↗

Long-term cytogenetic effects of antineoplastic treatment in relation to secondary leukemia.

Chromosome translocations are consistently present in leukemias and lymphomas and are likely to represent primary events in the development of these neoplasias. A study of conditions that predispose to leukemia could shed some light on the origin of these translocations and therefore help in clarifying their exact role in the process of neoplastic transformation. Based on this assumption, we studied a group of individuals treated with radiochemotherapy for previous lymphoma and who were at increased risk of developing a secondary leukemia. The group comprised 14 Hodgkin's disease patients, 11 non-Hodgkin's lymphoma patients, and 13 controls. The patients were in remission and had been off therapy for at least 6 months. Chromosomes were studied from phytohemagglutinin (PHA)-stimulated peripheral lymphocytes and from bone marrow cells by the direct method and after short-term cultures (72 hours). The latter were also exposed to 5-bromodeoxyuridine (BrdU). Metaphases were scored for chromosome breaks, gaps, and other rearrangements. The percentage of gaps and breaks was significantly higher in patients than in controls. The difference was induced by BrdU and was apparent in bone marrow cells, but not in peripheral lymphocytes. We conclude that individuals exposed to the action of mutagenic agents (radiochemotherapy) have an increased chromosome instability that could be related to their increased risk of developing a secondary leukemia.

Adolescent↗

Partial duplication of chromosome 1q preceding the development of an L3 lymphoblastic leukemia with t(8;14), secondary to treatment for Hodgkin's disease.

We report on a case of secondary lymphoblastic leukemia L3 in a patient treated with chemo- radiotherapy for a previous Hodgkin's disease. The typical chromosome translocation t(8;14) was found in association with a translocation t(9;19) and a marker chromosome 1, dup(1q). The same marker chromosome had been detected in a few cells of peripheral blood 2 years before the onset of the acute leukemia and may represent a proliferation-associated change, responsible for the initiation of the process of leukemogenesis.

Adult↗

Giant neutrophils with increased peroxidase activity. Another evidence of dysgranulopoiesis in AIDS.

Using the automated hematologic analyzer Technicon H6000, which classifies leukocytes by their size and peroxidase activity, the authors have observed in nine patients with full-blown acquired immune deficiency syndrome (AIDS) a consistent increase in peroxidase content of circulating neutrophils. The increase in peroxidase activity was homogeneous in three patients (P less than 0.05). The most striking finding, however, was the occurrence of single abnormal neutrophils with peroxidase activity higher than the major neutrophil population (i.e., HPX [high peroxidase] cells). The importance of this phenomenon was correlated with the clinical status, higher HPX values being found in patients with more advanced disease. These instrumental observations were associated with the morphologic finding of atypical neutrophils, much larger than normal, with irregular nuclei and abundant cytoplasm filled with peroxidase-positive granulations. Such cells represent, in the authors' experience, the most common expression of dysgranulopoiesis in AIDS.

Acquired Immunodeficiency Syndrome↗

Identification of blast cells in peripheral blood through automatic assessment of nuclear density: a new tool for monitoring patients with acute leukaemia.

The Technicon H*1 haematology system is provided with a new method for basophil count, neutrophil lobularity assessment and detection of blasts in peripheral blood through automated measurement of nuclear density. We compared the results of the H*1 blast flag with those of the microscope examination in 131 peripheral blood samples from 43 patients with acute leukaemia in different phases of their disease, to determine the degree of sensitivity and specificity of the system in this setting. In six patients at diagnosis or in overt relapse, all having large percentages of blasts at the manual differential count, a typical deformation of the profile of the mononuclear cell population on the display was consistently observed, regardless of the morphological subtype of leukaemic cell which was involved. Amongst 34 samples with 4-95% morphologically recognizable blasts on the peripheral blood film, the sensitivity of the system was 100% with no false negatives at all. In 43 samples, on the other hand, the H*1 blast flag was positive in the absence of any morphological evidence of blasts on the smear. These 'false positives', however, were always obtained from leucopenic patients who had more than 12% blast infiltration in the bone marrow, compared to the 0-6% value that was found in patients with a negative H*1 blast flag. These results suggest that the H*1 system is a highly sensitive tool for the detection in peripheral blood of even small concentration of leukaemic cells, which escape morphological identification.

Acute Disease↗