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Biomedical subjects

X López-Karpovitch

Publications and source records attributed to X López-Karpovitch.

At least 19 recordsLinked to original sources
PubMed2003

CD8+ chronic lymphocytic leukemia: an extensive characterization of a bizarre hybrid neoplasia.

Atypical chronic lymphocytic leukemia (CLL) expressing the CD8 antigen have a frequency of less than 0.5% of all cases, however, they are not yet been fully characterized. Herein a CD8+ CLL case was extensively studied. Besides the classical CLL antigen expression, an unusual presence of surface markers such as CD11c, CD56, and CD154 was observed. Moreover, gene expression of chemokine receptors belonging to the CCR family were clearly evidenced as well as mRNA for both, Th1 and Th2 cytokines. Likewise, granzyme A, B and perforin gene expression, cytotoxic T cell or NK enzymes were found. The intricate profile of membrane molecules and gene expression suggest that it could be favorable, rather than deletereous, for the maintainance of the neoplastic process.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Laparoscopic approach to fever of unknown origin.

BACKGROUND: Fever of unknown origin (FUO) is difficult to diagnose. Laparotomy is needed to establish the etiologic diagnosis in some patients. The aim of this study was to analyze the feasibility, safety, and success rate of a protocolized laparoscopy in patients with FUO. METHODS: An extensive clinical evaluation was performed before surgery. Laparoscopy included inspection of the abdominal cavity, wedge and tru-cut liver biopsies, lymph node biopsy, splenectomy, and bone marrow biopsy. Histologic analysis, permanent section analysis, and cultures were obtained. RESULTS: The study involved 15 patients with a mean age of 43.6 +/- 14.5 years. The mean operative time was 122 +/- 60 min. Minor complications occurred in 9% of the patients. One patient bled after surgery and underwent reoperation. There was no operative mortality. An etiologic diagnosis was made in 66% of the patients, and laparoscopy helped to rule out intraabdominal pathology in four additional patients, giving a total success rate of 93%. CONCLUSION: Protocolized laparoscopy in patients with FUO is safe, feasible, and accurate.

Feasibility Studies↗
PubMed2000

Flow cytometric analysis of glycosylphosphatidyl-inositol-anchored proteins to assess paroxysmal nocturnal hemoglobinuria clone size.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by total or partial deficiency of membrane proteins anchored to the cell surface through a glycosylphosphatidyl-inositol (GPI) moiety. The relationship between the size of the PNH clone, determined by the expression of GPI-anchored proteins (AP; CD14, CD48, CD55, CD59, and CD66b) on erythrocytes, lymphocytes, monocytes, and granulocytes using forward and side scatter analysis, and severity of the disease was evaluated in 19 PNH patients. CD55 antigen expression did not delineate abnormal erythrocytes as well as did anti-CD59. The proportion of monocytes deficient in CD55, CD59, CD48, and CD14 (48-97%) and of granulocytes deficient in CD55, CD59, and CD66b (60-99%) was greater than the proportion of erythrocytes deficient in CD59 (24-95%) and the proportion of lymphocytes deficient in CD55 and CD59 (30-98%). There were no significant correlations among reticulocyte, leukocyte, and platelet counts and GPI-AP-deficient immunophenotypes in red and white blood cells. However, high coefficients of determination were seen between hemoglobin levels and granulocytes deficient in CD59 (r(2) = 0.76), CD55 (r(2) = 0.74), and CD66b (r(2) = 0.74) antigens and between hemoglobin and monocytes deficient in CD55 (r(2) = 0.73), CD59 (r(2) = 0.80), and CD14 (r(2) = 0.75) antigens. These results are interpreted as indicating that the size of PNH clone is better assessed by immunophenotypic analysis of monocytes and granulocytes rather than of lymphocytes and erythrocytes.

Adult↗
PubMed2000

Detection of platelet-associated immunoglobulins by flow cytometry for the diagnosis of immune thrombocytopenia: a prospective study and critical review.

BACKGROUND AND OBJECTIVE: Flow cytometry (FC) to identify platelet-associated (PA) immunoglobulin (Ig) is a potentially useful diagnostic test for idiopathic thrombocytopenic purpura (ITP). However, the restricted application of PAIg measurement to thrombocytopenic populations primarily comprised of ITP patients will artificially enhance the test's diagnostic specificity. For this reason, we performed a prospective study in which the results of a sensitive technique for detecting PAIg, as is FC, were correlated to the cause of the thrombocytopenia. DESIGN AND METHODS: A total of 118 patients with platelet counts <100 x 10(9)/L and 30 normal donors with a platelet count >200 x 10(9)/L were studied for PAIg employing a flow cytometer. Forty-two children and 20 adults were diagnosed as having immune thrombocytopenia and 27 children and 29 adults had nonimmune thrombocytopenia of different etiology. RESULTS: Raised levels of PAIg were found in 56/62 patients with immune thrombocytopenia and in 34/56 patients with non-immune thrombocytopenia. Diagnostic values of PAIg for the detection of immune thrombocytopenia were: sensitivity 90.3% and specificity 39. 3%. An enzyme-linked immunoabsorbant assay (ELISA) for the detection of autoantibodies to platelet glycoprotein (GP) complexes was used in adults, 9 with immune-related thrombocytopenia and 16 with non-immune thrombocytopenia, in order to determine the true non-specific nature of the positive PAIg test. By ELISA, 8/9 patients with immune thrombocytopenia and 7/16 with non-immune thrombocytopenic disorders showed autoantibodies to platelet GP complexes. INTERPRETATION AND CONCLUSIONS: PAIg detection by FC constitutes a sensitive but non-specific assay thus making it unnecessary and inappropriate for establishing the diagnosis of ITP.

Adolescent↗
PubMed1998

Light scatter and immunophenotypic characteristics of blast cells in typical acute promyelocytic leukemia and its variant.

Acute promyelocytic leukemia (APL), defined by the French-American-British (FAB) classification as the M3 subtype of acute myeloblastic leukemia (AML), is readily diagnosed by direct cytomorphologic examination. The potential difficulty in recognizing the microgranular variant of APL (M3v) stems from the morphological characteristics of APL leukemic cells, which resemble monocytes. From 109 newly diagnosed acute leukemic patients, 48 were classified as AML and 16 of these patients (33%) had APL Mononuclear cells (MNC) of all APL patients were analyzed by flow cytometry for immunophenotypic features and forward and right angle scatter (FW-SC/RT-SC) light characteristics. Two clearly different FW-SC/RT-SC distribution patterns were recognized and defined as hypergranular (mature cells) and hypogranular (immature cells). Correlation between FW-SC/RT-SC patterns and the FAB system was poor: from eight patients classified as M3, six had the hypergranular pattern and two had the hypogranular pattern; from eight cases with M3, five and three patients had hypogranular and hypergranular patterns, respectively. The most relevant cellular immunophenotypic feature was the high frequency of CD34+ cases (5/7) recorded exclusively in patients with the hypogranular pattern. An interesting finding was that MNCs of all APL patients changed color from beige to green in the course of 3-4 h, whereas none of the 93 specimens of non-M3 acute leukemia cases showed this phenomenon. Summarizing, the FW-SC/RT-SC characteristics of APL blast cells along with the immunophenotype may represent an objective and reproducible measurement system to distinguish microgranular (M3v) from typical (M3) APL In addition, the present study has identified another unique feature of APL based on the green color of their blast cells imparted by the high content in myeloperoxidase.

Adolescent↗
PubMed1998

Effect of androgen therapy and anemia on serum erythropoietin levels in patients with aplastic anemia and myelodysplastic syndromes.

Immunoreactive serum erythropoietin (EPO) was measured in anemic and non-anemic patients with acquired non-severe aplastic anemia (AA; n = 22) and myelodysplastic syndromes (MDS; n = 31) receiving or not androgens to examine the effect of androgen therapy and anemia on EPO levels in these disorders. Soluble transferrin receptor (TfR) and absolute reticulocyte count (ARC) were also assayed in order to evaluate erythropoietic activity. AA and MDS patients were stratified for anemia and androgen treatment as follows: 12 untreated anemic patients; 17 anemic patients during androgen therapy; 14 non-anemic patients without any treatment (> 1 year); and 10 non-anemic patients on androgen therapy. Although EPO levels in non-anemic patients were significantly higher than in healthy controls (n = 29) no statistically significant differences in Hb and EPO values were found between non-anemic patients receiving or not androgen therapy. In the linear regression analysis between Hb and log EPO concentration, no statistically significant differences in the slopes between untreated and androgen-treated anemic groups nor between both groups and patients with iron deficiency anemia (n = 23) were observed. However, the y intercept (log EPO) of regression line was significantly higher in androgen-treated anemic patients than in the androgen therapy-free anemic group. Serum TfR levels were higher in treated than in untreated anemic patients, whereas ARC was not different between both groups. These data seemingly indicate that (1) androgens at pharmacological doses do not increase serum EPO levels in non-anemic AA and MDS patients, and (2) in patients with AA and MDS, androgen-driven EPO stimulation is appreciably enhanced by anemia.

Adult↗
PubMed1998

Laparoscopic versus open splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Laparoscopic splenectomy (LS) has been proposed as a substitute to open splenectomy (OS) in the treatment of immune thrombocytopenic purpura (ITP). The aim of this study was to compare two cohorts of patients with ITP who underwent OS or LS. PATIENTS AND METHODS: From February 1990 to January 1997, 27 patients underwent OS and 22 LS. Perioperative characteristics, outcomes, and complications were comparatively analyzed. RESULTS: Mean age was 38 years (+/- 16) in the OS group, and 39 (+/- 16) in the LS group; the male: female ratio was 1:2 in both groups. Median preoperative platelet count was 16 x 10(9)/L (range 2 to 186 x 10(9)/L) in the OS group, and 50 x 10(9)/L (2 to 241 x 10(9)/L) in the LS group. Mean operative time was 2.7 hours (+/- 0.7) for OS, and 4.5 hours (+/- 1) for LS (P <0.0001). Two conversions to laparotomy occurred in the LS group. A total of 14 complications occurred in 10 patients of the OS group; 8 complications occurred in 6 patients of the LS group. Two patients died in the OS group and 1 in the LS group. Mean postoperative discharge was 6 days (3 to 44) in the OS group and 4 days (2 to 11) in the LS group (P <0.02). Response rates were similar in both groups. CONCLUSIONS: Laparoscopic splenectomy is comparable to OS in terms of efficacy and safety, and it is associated with a shorter hospital stay.

Adult↗
PubMed1997

Circulating lymphocyte subpopulations and activated T and B cells in patients with chagasic and non-chagasic myocardiopathy.

Trypanosoma cruzi causes a profound immune depression in the infected host, and a small proportion of chagasic patients will develop a chronic disease characterized by myocardiopathy. There is evidence suggesting that dilated non-chagasic cardiomyopathy may be mediated by an immunological mechanism. In an attempt to distinguish abnormal immunoregulatory cell patterns in both dilated myocardiopathies, total and activated T and B lymphocyte subpopulations were measured by flow cytometry and double-labeling in whole blood samples from patients with dilated myocardiopathy, 10 with positive serological tests for T. cruzi and 9 with different non-chagasic cardiomyopathies. Several significant differences were found between both groups of patients and 13 sex- and age-matched apparently healthy controls. Chagasic patients besides showing clear decrease in absolute numbers of CD3+/CD71+ and CD8+/CD25+ cell populations also had a significant increase in CD19+, CD10+, and CD19+/HLA-DR+ cell subsets, as well as high helper/ suppressor cell ratio. These findings suggest that concurrently with T cell diminution, which involved activated T lymphocytes displaying suppressor/cytotoxic immunophenotype, chronic chagasic patients with myocardiopathy showed elevated numbers of total and activated B lymphocytes. Patients with dilated non-chagasic myocardiopathy had significantly increased numbers of activated T cells (CD3+/CD25+, CD8+/CD25+, and CD8+/HLA-DR+) and total and activated B lymphocytes (CD10+, CD19+, CD19+HLA-DR+). These data support the notion that dilated myocardiopathies other than the chagasics may be associated with immunological abnormalities.

Adult↗
PubMed1995

Circulating colony-forming units of granulocytes/monocytes in patients with chronic myeloid leukemia before and during busulfan treatment.

The number of colony-forming units of granulocytes/monocytes (CFU-GM) in the peripheral blood of 7 patients with chronic myeloid leukemia (CML) in chronic phase (CP) receiving standard doses of busulfan (BSF, 0.1-0.2 mg/kg/day p.o.) was compared to that found in 8 patients with CML in CP not previously treated in order to establish if non-myeloablative chemotherapy mobilizes committed granulomonocytic progenitor cells into the circulation. The number (mean +/- SEM) of spontaneous CFU-GM in untreated patients was similar to that recorded in 10 sex- and age-matched controls, 2.6 +/- 1.9 and 3.5 +/- 2.1, respectively. BSF-treated patients showed significantly more spontaneous CFU-GM (13.9 +/- 7.5) than controls and untreated patients. Addition of recombinant human granulocyte/monocyte colony-stimulating factor to cultures promoted colony growth in controls but not in untreated and BSF-treated patients. These data seemingly indicate that: 1) administration of standard non-myeloablative doses of BSF to patients with CML in CP mobilizes CFU-GM into the circulation and 2) BSF therapy selects a granulomonocytic colony-forming progenitor cell population with increased autonomous growth potential. These findings may contribute to the understanding of the therapeutic role of BSF in CML.

Adult↗
PubMed1994

Cellular and humoral immune parameters in women with pathological hyperprolactinemia before and during treatment with bromocriptine.

PROBLEM: Experimental and clinical evidence has suggested an immunostimulatory effect of prolactin and that bromocriptine, an inhibitor of prolactin release, counteracts the actions of prolactin on the immune system. The aim of this study was to determine the impact of elevated serum prolactin levels on the immune system in patients with pathological hyperprolactinemia. METHOD: For this purpose, parameters of the cellular and humoral immune system were studied in six women with prolactinomas and one with idiopathic hyperprolactinemia. Studies were performed when serum prolactin concentrations were high as well as during different phases of the menstrual cycle when prolactin levels had been normalized through treatment with bromocriptine. RESULTS: Hyperprolactinemic subjects, when compared with six age-matched normal women, had significantly higher percentages of total lymphocytes and CD2+ cells. Elevation of CD4+ cells was also observed although to a lesser extent. Bromocriptine-treated patients, when compared with normal women were characterized by increased numbers of total lymphocytes and CD4+ cells, decreased percentage of CD8+ cells, and increased concentrations of serum IgM. These last two findings were also significantly different when compared to those observed in hyperprolactinemia. CONCLUSION: In this study we have described the changes on cellular and immune parameters in patients with hyperprolactinemia before and during bromocriptine therapy, which support the links of communications between the immune and endocrine systems in humans.

Adolescent↗
PubMed1992

Treatment of methimazole-induced severe aplastic anemia with recombinant human granulocyte-monocyte colony-stimulating factor and glucocorticosteroids.

The in vivo response to recombinant human granulocyte-monocyte colony-stimulating factor (rHu GM-CSF) in facilitating the reconstitution of granulomonopoiesis was evaluated in a patient with Graves' disease who developed severe aplastic anemia during methimazole therapy. After 10 days of treatment with rHu GM-CSF, the neutrophil and monocyte counts rose to 1.65 x 10(9)/l and 0.41 x 10(9)/l, respectively. However, the patient was still dependent on erythrocyte and platelet transfusions. Two days after rHu GM-CSF withdrawal, the neutrophil count dropped off to 0.41 x 10(9)/l.rHu GM-CSF was reinitiated for 2 days along with glucocorticosteroids. With this combined therapeutic approach, the neutrophil count returned to normal and remained stable, and both Hb and platelet values began to improve. It is concluded that the combination of rHu GM-CSF and glucocorticosteroids can be used as a therapeutic option that may lead to beneficial results in drug-induced aplastic anemia.

Adolescent↗
PubMed1989

Low doses of high-potency antithymocyte globulin (ATG) in severe aplastic anemia: experience with the Mexican ATG.

Twenty patients with severe aplastic anemia (SAA) were treated with low doses (1-5 mg/kg/day) of a high-potency antithymocyte globulin (ATG) produced in Mexico, shown to have at least a 10-fold potency as compared with other globulins of commercial sources. Patients received ATG within a 10-day period, every other day (5 doses) at a dose of 1 mg/kg/day (4 courses), 2 mg/kg/day (12 courses) or 5 mg/kg/day (8 courses). Four patients received 2 consecutive courses of different doses of ATG. A response rate of 42% was recorded in the group, assessed by means of increases in reticulocytes, granulocytes or platelets. One patient showed a complete remission. The 570-day survival of the group was 51%. It is concluded that the domestically produced ATG is useful in the treatment of some patients with SAA in Mexico.

Adolescent↗
PubMed1989

Changes in peripheral blood mononuclear cell subpopulations during antithymocyte globulin therapy for severe aplastic anemia.

The short-term effect of a domestically produced equine antithymocyte globulin (ATG) was analyzed in 6 patients with acquired severe aplastic anemia (AA). All patients received 5 doses of ATG every other day in a 60-min intravenous infusion. Five peripheral blood immunoregulatory mononuclear cell (MNC) subsets, defined by monoclonal antibodies, were enumerated before and 24 h after each application of ATG. Following the first dose of ATG there was a significant and transient reduction in the absolute number of helper T lymphocytes. There was no statistically significant difference pre-ATG to post-ATG in the absolute number of MNC expressing activation antigen Tac (interleukin-2 receptor). However, Tac+ cells, which were significantly increased before ATG therapy, decreased to nearly normal levels after the fourth dose of ATG. A significant and sustained increment in the absolute number of monocytes (CD14+ cells) occurred following the third dose of ATG. The absolute numbers of MNC, suppressor T lymphocytes and cells bearing HLA-DR antigen remain without significant change along ATG treatment. These results suggest that: (a) Tac+ cells are probably involved in the pathogenesis of AA; (b) the target of ATG may be a Tac+ cell, and (c) ATG may stimulate monopoiesis.

Acute Disease↗
PubMed1989

Circulating colony-forming units of granulocytes and monocytes/macrophages in systemic lupus erythematosus.

In systemic lupus erythematosus (SLE) patients, in vitro bone marrow (BM) colony-forming units of granulocytes and monocytes/macrophages (CFU-GM) are decreased, suggesting that granulomonopoietic failure may play an important role in the mechanism of peripheral blood (PB) depletion of neutrophils and monocytes. No information concerning CFU-GM in PB of patients with SLE is available. The present study was undertaken in order to determine whether SLE itself and the inactive or active stage of disease would modify the number of GFU-GM in PB samples from 20 treatment-free SLE women, 12 inactive and eight active. CFU-GM growth was significantly decreased in both inactive (P = 0.018) and active (P = 0.008) SLE patients as compared with controls (n = 8). The difference in CFU-GM growth between SLE groups was not significant. These results indicate that the number of circulating CFU-GM is significantly reduced in patients with SLE regardless of disease activity or remission.

Female↗
PubMed1985

Release of granulocyte-macrophage colony-inhibiting activity by normal human postthymic precursor cells.

Seven normal human peripheral blood cell fractions (buffy coat, mononuclear cells, non-T, T, Fc-IgM receptor-depleted T-lymphocyte, Fc-IgG receptor-depleted T-lymphocyte, and autologous rosette-forming T-cell-depleted T-lymphocyte subpopulations) treated with phytohemagglutinin (PHA) were examined for the production of granulocyte-macrophage colony-stimulating activity (CSA). It was found that medium conditioned by a T-lymphocyte subpopulation depleted of autologous rosette-forming T-cells (Tar cells, a postthymic precursor subpopulation that inhibits Ig synthesis) stimulated colony-forming units of granulocyte and macrophages (CFU-GM) to a greater extent than did the other conditioned media (CM) analyzed. Based on this finding, CM from an enriched Tar subpopulation was prepared and thus showed that PHA-treated Tar cells release a factor capable of inhibiting CFU-GM growth. The inhibitory activity of this factor persisted-after heat inactivation, suggesting that cause of the colony-inhibiting activity (CIA) is other than interferon. Further studies revealed that Tar-derived inhibitory factor acts either directly upon CFU-GM or via monocytes/macrophages (M phi/Ma), enhancing CIA, and not the level of CSA production by M phi/Ma. The overall data are interpreted as demonstrating the presence of CIA in a specific T-lymphocyte subpopulation that may represent a new relationship between lymphocytic and myelocytic systems in the human.

Colony-Forming Units Assay↗
PubMed1984

Ferritin in normal human peripheral blood T-lymphocyte subpopulations.

Six peripheral blood lymphoid fractions (total lymphocytes, non-T, T, Tar (autologous rosette-forming T cells/precursor), T mu (helper), and T gamma (suppressor) lymphocytes) isolated through rosetting procedures were examined for the presence of ferritin by a direct immunofluorescence technique. Although ferritin was present in all lymphoid fractions studied, a significantly higher proportion of ferritin-containing cells were detected in the T-cell fraction than in the non-T-cell fraction, (mean +/- SD = 7.9 +/- 1.6% and 5.0 +/- 1.2%, respectively). T mu- and T gamma-cell fractions showed a twofold increase in the number of ferritin-positive cells (14.1 +/- 1.4% and 15.4 +/- 2.6%, respectively), as compared with Tar (7.0 +/- 0.9%)-and total lymphocyte (6.9 +/- 1.3%)-cell fractions. These results indicate that ferritin is preferentially distributed in T mu and T gamma lymphocytes and may constitute the basis for explaining some of the roles exercised by these cells in the control of other biological systems.

Cell Separation↗