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Biomedical subjects

A Ruiz-Arguelles

Publications and source records attributed to A Ruiz-Arguelles.

At least 19 recordsLinked to original sources
PubMed1999

Clinically useful information provided by the flow cytometric immunophenotyping of hematological malignancies: current status and future directions.

BACKGROUND: At present, immunophenotyping of hematological malignancies represents one of the most relevant clinical applications of flow cytometry. In recent years, its use has extended from clinical research to diagnostic laboratories. The aim of this report is to critically review the type of information provided by the flow cytometric immunophenotyping of hematological malignancies and its clinical impact as well as to highlight its potential future applications. METHODS: The currently available information, including that provided by different international consensus groups on the phenotypic characterization of hematologic malignancies, was reviewed. Additionally, recent reports on the immunophenotypic analysis of hematological malignancies published in hematology, oncology, pathology, immunology, and cell biology journals were also analyzed. RESULTS: A careful review of the literature showed that in spite of the well-established utility of immunophenotyping for the diagnosis, classification, prognostic stratification, and monitoring of hematological malignancies, only a small part of the information on the immunophenotypic characteristics of pathological hemopoietic cells has been used routinely. Specific and sensitive identification of neoplastic cells and their accurate enumeration and phenotypic characterization represent the major aims of these procedures. Similarities between leukemic and healthy cells allow the establishment of the lineage and maturation stage of the pathologic cells, this information being of great utility for the diagnosis, classification, and prognostic evaluation of different subtypes of hematological malignancies. On the other hand, the phenotypic aberrations displayed by leukemic cells could allow the selection of cases carrying specific genetic abnormalities in which further confirmatory molecular studies will be performed. CONCLUSIONS: The information provided by the flow cytometric immunophenotyping of hematological malignancies is of great clinical utility, with a major challenge for the near future being the standardization of technical procedures, data interpretation, and reporting.

Flow Cytometry↗
PubMed1996

General concepts about cell sorting techniques.

Research involving cell analysis frequently requires isolation of certain cell types or subcellular components either as a final objective or as a preparative tool for further assays. At present, there are a high number of cell sorting methods that are suitable for being used in the clinical laboratory. These methods can be divided into two major groups: (1) bulk sorters and (2) single-cell-based sorters. This latter group mainly refers to fluorescence-activated cell sorting (FACS) by flow cytometry (FCM). In both cases, separation of cell subsets is based on their classification according to one or more cell characteristics. In bulk sorters, cell classification and sorting are usually achieved in a single step; by contrast, in FACS techniques, these two steps are independent sequential processes. In addition, bulk sorters generally use a single-cell characteristic to isolate cell subsets and have a higher throughput rate, as compared with FACS by FCM, where several parameters can be used simultaneously to classify cells for their further isolation. As a consequence of the mechanisms underlying these two cell sorting methods, the balance between cell purity and cell recovery on the sorted fraction are generally different, the single-cell-based methods usually providing both a higher purity and recovery. Thus, in practice, bulk separation methods are frequently used either as a preparative step for FCM-based cell sorting or for the enrichment of the sample in specific cell subsets, when a higher throughput rate is required; in contrast, FACS by FCM is selected for the isolation of cell subsets when a high purity and, especially, recovery of a specific subpopulation of cells present in a sample are needed.

Animals↗
PubMed1995

Serum antibodies to distinct epitopes of the tissue-type plasminogen activator (t-PA) in patients with systemic lupus erythematosus.

Defective fibrinolysis due to decreased tissue-type plasminogen activator (t-PA) activity is a well-established finding in patients with systemic lupus erythematosus (SLE). The possibility that this decrease in t-PA activity may be related to the presence of autoantibodies directed against t-PA, and the possible role of these autoantibodies in the pathophysiology of fibrinolysis in SLE, were investigated. Serum samples from 115 SLE patients and 63 normal volunteers were analyzed for the presence of such antibodies. The search for antibodies to t-PA was performed by means of several systems, allowing for the identification of epitopes presented in different conformational physical states of t-PA: free or associated to its inhibitor (PAI-1) in plasma, specifically bound to fibrin surface, or passively adsorbed to solid supports. Antibodies in variable amounts were detected by all systems used; however, t-PA activity was not inhibited by the IgG fraction of the positive sera in a fibrin-agar fibrinolysis system. Moreover, the demonstration of serum anti-t-PA antibodies was not associated with clinical or laboratory abnormalities related to vasoocclusive episodes. These results indicate that, as in the case of other autoantibodies, their detection in serum does not imply their direct participation in the pathophysiology of thrombosis in SLE.

Adolescent↗
PubMed1993

Presence of serum antibodies to coagulation protein C in patients with systemic lupus erythematosus is not associated with antigenic or functional protein C deficiencies.

Antibodies directed to immunopurified coagulation protein C (PC) were investigated in serum samples from 108 patients with systemic lupus erythematosus (SLE) and found in 12 of them. However, their presence was not associated with antigenic or functional deficiencies of PC, which were documented in 6 and 17 patients, respectively.

Antibodies↗
PubMed1989

Demonstration of a cross-reactive idiotype (IdRQ) in rheumatoid factors from patients with rheumatoid arthritis but not in rheumatoid factors from healthy, aged subjects.

A human monoclonal IgM kappa paraprotein with rheumatoid factor (RF) activity was used to elicit antiidiotypic antibodies in rabbits. The antiidiotypic antiserum thus obtained reacted with samples from 40% of 72 rheumatoid arthritis patients, but not with any of the samples from 22 aged control subjects having serum RF. Our findings suggest that, despite the similarities between RF from rheumatoid arthritis patients and that from healthy individuals, the expression of V region genes may be different in healthy subjects and those with the disease.

Adult↗
PubMed1989

Acquired protein C deficiency in a patient with primary antiphospholipid syndrome. Relationship to reactivity of anticardiolipin antibody with thrombomodulin.

A 16-year-old boy had recurrent venous thromboses and pulmonary thromboembolism that caused him pulmonary hypertension. He also had livedo reticularis, thrombocytopenia and high titer IgG antiphospholipid (cardiolipin) antibodies. In the absence of clinical and laboratory evidence of SLE, he was considered to have a primary antiphospholipid syndrome. Coagulation studies revealed a functional deficiency of protein C although it was present in normal antigenic amounts. Since both his parents had normal functional and antigenic protein C findings, his deficiency was considered acquired. The reactivity of the anticardiolipin antibodies could be decreased in a dose dependent fashion when preincubated with increasing amounts of thrombomodulin, a protein required for protein C activation at the endothelial cell membrane. This interaction of antiphospholipid antibodies with thrombomodulin may help explain the occurrence of thrombosis in some patients with antiphospholipid antibodies, despite the behavior in vitro of these antibodies as circulating anticoagulants.

Adolescent↗
PubMed1988

Increased detection of human immunodeficiency virus antigen carriers by simultaneous assay of plasma and extracts from resting and phytohaemagglutinin-stimulated peripheral blood mononuclear cells.

Antigenaemia due to human immunodeficiency virus (HIV) is thought to be significant either before the appearance of a specific antibody response, or after its decline during terminal stages. In order to increase the rate of detection of HIV antigen carriers, regardless of the stage or despite the presence of specific serum antibodies, we assayed, simultaneously, plasma samples and extracts from resting and phytohaemagglutinin-stimulated mononuclear cells from 25 infected, anti-body-positive individuals and 10 healthy, antibody-negative female volunteer blood donors. We detected the presence of HIV antigen in at least one of the three types of specimens obtained from all the 25 infected subjects but in none of the 10 healthy blood donors. This approach might prove most useful for the study of patients with controversial or equivocal antibody test results.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Spontaneous reversal of acquired autoimmune dysfibrinogenemia probably due to an antiidiotypic antibody directed to an interspecies cross-reactive idiotype expressed on antifibrinogen antibodies.

A young man with a long history of abnormal bleeding was seen in January 1985. Coagulation tests showed dysfibrinogenemia and an antifibrinogen autoantibody was demonstrable in his serum. This antibody, when purified, was capable of inhibiting the polymerization of normal fibrin monomers, apparently through binding to the alpha fibrinogen chain. 6 mo later the patient was asymptomatic, coagulation tests were normal, and the antifibrinogen autoantibody was barely detectable. At this time, affinity-purified autologous and rabbit antifibrinogen antibodies were capable of absorbing an IgG kappa antibody from the patient's serum, which reacted indistinctly with both autologous and xenogeneic antifibrinogen antibodies in enzyme immunoassays. It has been concluded that the patient's dysfibrinogenemia was the result of an antifibrinogen autoantibody, and that later on an anti-idiotype antibody, which binds an interspecies cross-reactive idiotype expressed on anti-human fibrinogen antibodies, inhibited the production of the antifibrinogen autoantibody which led to the remission of the disorder.

Adult↗
PubMed1987

Prothrombin "Mexico City," an asymptomatic autosomal dominant prothrombin variant.

A functionally normal but structurally abnormal prothrombin variant was found in a Mexican family. Immunoisoelectricfocusing studies revealed that this variant has a more acidic isoelectric point (4.01) than normal prothrombin (4.29), but it proved to have a normal molecular weight as assessed by sodium-dodecyl-sulphate polyacrylamide gel electrophoresis. Two-dimensional immunoelectrophoresis studies showed an abnormal cleavage of the prothrombin molecule by factor Xa and Echis carinatus venom as well, despite the fact that both yield functionally normal thrombin molecules. Finally, the ability of the molecule to bind calcium ions as well as its overall antigenic structure were investigated and found to be normal. These results taken together suggest a simple (substitution or translocation) mutation at the fragment 2 level. Since this prothrombin variant is different from others described previously, the name "Mexico City" is proposed to identify it.

Adult↗
PubMed1984

Effect of bacterial immunization on experimental reflux nephropathy.

This study was designed to test the hypothesis that young animals with vesicoureteral reflux might be more vulnerable to renal parenchymal infection by bacteria to which they had not been previously exposed. Forty-four crossbred male piglets had surgical induction of vesicoureteral reflux at 2 weeks of age and introduction of urinary tract infection at 6 weeks. They were sacrificed at 12 weeks of age. Between the ages of 2 and 6 weeks, 22 piglets received subcutaneous injections of formalin-killed Escherichia coli in incomplete Freund's adjuvant as described. The remaining 22 piglets received incomplete Freund's adjuvant and vehicle alone. The antibody responses to antigenic challenge were weak to moderate. Immunized animals tended to have less renal scarring and better renal tubular uptake of dimercaptosuccinic acid, in addition to significantly lower serum creatinine values (p less than 0.001) and less mesangial cell proliferation in glomeruli (p = 0.05). We conclude that previous exposure to a specific bacterial strain and bacterial immunization have at least a mild protective effect on the development of reflux nephropathy.

Animals↗
PubMed1984

'Incomplete' pyroglobulin-gamma disease in a patient with osteosclerotic myeloma.

A 50-year-old female, heterozygous for beta-thalassaemia was found to have a lytic lesion surrounded by osteosclerotic tissue in the 1st lumbar vertebra. Aspiration of the lesion showed 100% atypical plasma cells. The bone marrow contained 17% myeloma cells. Despite normal electrophoresis and immunoelectrophoresis of serum and urine, 'rouleaux' formation was pronounced. Treatment of the serum sample with 2-mercaptoethanol and heat (56 degrees C) disclosed an uncommon pyroglobulin. Analysis of the ammonium sulphate precipitate of the serum by sodium-dodecyl-sulphate polyacrylamide gel electrophoresis revealed a 43 kD component with higher anodic mobility than normal gamma chains. Ultrafiltration column chromatography of the serum revealed a narrow spike of approximately 4 S that contained gamma heavy chain antigenic determinants in addition to normal 7 S IgG.

Electrophoresis, Polyacrylamide Gel↗
PubMed1981

Laser nephelometry quantitation of fibrinogen-related antigens.

A laser nephelometric procedure to quantitate fibrinogen related antigens (FRA), that joined the best characteristics of the immunological available techniques, is proposed. It is sensitive, rapid, simple, reproducible, antiserum saving and accurate since it correlates very well with the tanned red cell hemagglutination inhibition immunoassay (TRCHII) at the most commonly found clinical levels (r = 0.98, p less than 0.0005), but with the advantage of a more objective quantitation and thus, reliable for any concentration of FRA. Prepared samples of different known levels of fibrinogen, assayed with the laser method and the TRCHII, showed a higher correlation with the laser procedure (r = 0.97, p less than 0.0005) than the obtained with the TRCHII (r = 0.85, p less than 0.001). The technic is useful in emergency situations, routine work and research.

Adolescent↗
PubMed1981

Optimal conditions in [3H]-thymidine uptake studies to prevent radiation damage to cells. A scintimetric and cytofluorographic analysis.

Cells subjected to nucleoside incorporation studies using radiolabelled materials may suffer radiation damage that can alter the results. We did scintimetric and cytofluorographic analysis to confirm this and to determine the optimal experimental doses of, and exposure times to, [3H]-TdR, in order to prevent or minimize such radiation damage to cells. We found that cultures should be pulsed with 0.125 microCi for 14 hr when stimulated with phytohaemagglutinin 0.125 microCi for 18 hr when stimulated with pokeweed mitogen, 0.5 microCi for 8 hr when stimulated with concanavalin A and 0.5 microCi for 8 hr when subject to allogeneic stimulus, in order to achieve optimal incorporation with minimal disturbance of the cell cycle.

Cell Cycle↗