PubMed Health⌕ Search

Biomedical subjects

J Ubeda

Publications and source records attributed to J Ubeda.

At least 19 recordsLinked to original sources
PubMed2001

Flow cytometry using the monoclonal antibody CD10-Pe/Cy5 is a useful tool to identify follicular lymphoma cells.

Follicular lymphoma (FL) is a specific entity defined by characteristic histology, phenotype and molecular rearrangements. Classically, reactivity for CD19, CD10, and strong positivity for the surface light chain immunoglobulin (SIg) are considered to be phenotypic signs typically expressed in FL. In practice, this pattern is difficult to identify since most neoplastic cells analysed by flow cytometry (FC) show weak intensity for CD19-Pe/Cy5 and for SIg and negativity for CD10-FITC. We used triple antigen combinations including two monoclonal antibodies (MoAbs) against CD10 (CD10-FITC and CD10-Pe/Cy5) and a long-distance polymerase chain reaction (PCR) approach to establish the phenotypic pattern of neoplastic cells carrying t(14;18)(q32;q21). Neoplastic cells showed the following immunophenotype: stronger reactivity against CD20 than against CD19, positivity for CD22 and SIg and negativity for CD5, CD11c and CD10-FITC. Characteristically, CD10-Pe/Cy5 was expressed in all the samples with positive bcl-2/JH rearrangements. In FL, there was a high correlation between histologic diagnosis and reactivity against CD10-Pe/Cy5 (96% cases). In diffuse large cell lymphomas (DLCL), CD10-Pe/Cy5 identified positive cases with t(14;18)(q32;q21) chromosomal translocation, whereas Burkitt lymphomas showed all cases reactivity against CD10-Pe/Cy5. In conclusion, CD10-Pe/Cy5 is a useful antibody for identifying neoplastic cells carrying t(14;18)(q32;q21) in FL and DLCL. In combination with other MoAbs, anti-CD10 (HI10a, Cy-Chrome) can be used to identify a characteristic phenotypic profile of FL against other lymphoproliferative disorders.

Adult↗
PubMed2001

[Anesthesia for carotid paraganglioma exeresis. Report of 3 cases].

This report of carotid paraganglioma excision in three patients discusses differential diagnosis, preoperative assessment, preoperative embolization of the tumor, monitoring of anesthesia including cerebral oximetry, and postoperative complications. We consider cerebral protection to be essential during carotid paraganglioma surgery. Such protection may be provided by drugs such as sodium thiopental and by temporarily shunting the internal carotid artery. Preoperative angiography is also important for evaluating retrograde circulation through Willis's polygon and to examine the arteries irrigating the tumor. Information thus obtained helps establish the need for presurgical embolization of the tumor, thereby possibly reducing the risks, such as obstructive hematoma that are inherent to the procedure. Finally, in our opinion, full monitoring should include cerebral oximetry so that possible complications can be detected and resolved.

Adult↗
PubMed2000

CD66 expression in acute leukaemia.

Antibodies against CD66 identify antigens from the carcinoembryonic antigen (CEA) family of proteins, which belong to the immunoglobulin gene superfamily. Despite being usually restricted to cells of myeloid or monocytic origin, CD66 expression has also been reported in blasts from children with B-cell lineage acute lymphocytic leukaemia (ALL). An analysis of the CD66 expression was undertaken in a series of acute leukaemia patients. Antigenic expression was analysed using triple combinations of monoclonal antibodies (mAbs) in forty-five patients. The CD66 Kat4 fluorescein isothiocyanate clone was purchased from Dako (Glostrup, Denmark). CD66 was expressed in 2 of 29 patients with AML (acute myeloblastic leukemia) (6.8%) and in 8 of 12 patients with B-cell lineage ALL (66.7%; P<0.001); in blast crisis (BC) of chronic myelocytic leukaemia (CML), CD66 was expressed in two patients with lymphoid BC but not in the two with myeloid BC. The co-expression of CD66 with other myeloid antigens was observed in all CD66+ ALL/ Ly-BC cases tested: CD 13 in six patients, CD33 in seven and CD117 in two patients. The CD66 expression is more frequent in ALL than in AML. Furthermore, we analysed minimal residual disease (MRD) in eight patients in complete remission. CD66 expression was associated with an abnormal B-cell differentiation pattern and with increases in CD34/CD19+ cells in all but one case. These findings suggest that an aberrant expression of CD66 could be used to investigate MRD in ALL. The association between CD66 reactivity and bcr-abl in adult ALL remains to be investigated.

Acute Disease↗
PubMed1999

Interaction of mitogen-activated protein kinases with the kinase interaction motif of the tyrosine phosphatase PTP-SL provides substrate specificity and retains ERK2 in the cytoplasm.

ERK1 and ERK2 associate with the tyrosine phosphatase PTP-SL through a kinase interaction motif (KIM) located in the juxtamembrane region of PTP-SL. A glutathione S-transferase (GST)-PTP-SL fusion protein containing the KIM associated with ERK1 and ERK2 as well as with p38/HOG, but not with the related JNK1 kinase or with protein kinase A or C. Accordingly, ERK2 showed in vitro substrate specificity to phosphorylate GST-PTP-SL in comparison with GST-c-Jun. Furthermore, tyrosine dephosphorylation of ERK2 by the PTP-SLDeltaKIM mutant was impaired. The in vitro association of ERK1/2 with GST-PTP-SL was highly stable; however, low concentrations of nucleotides partially dissociated the ERK1/2.PTP-SL complex. Partial deletions of the KIM abrogated the association of PTP-SL with ERK1/2, indicating that KIM integrity is required for interaction. Amino acid substitution analysis revealed that Arg and Leu residues within the KIM are essential for the interaction and suggested a regulatory role for Ser(231). Finally, coexpression of PTP-SL and ERK2 in COS-7 cells resulted in the retention of ERK2 in the cytoplasm in a KIM-dependent manner. Our results demonstrate that the noncatalytic region of PTP-SL associates with mitogen-activated protein kinases with high affinity and specificity, providing a mechanism for substrate specificity, and suggest a role for PTP-SL in the regulation of mitogen-activated protein kinase translocation to the nucleus upon activation.

Amino Acid Sequence↗
PubMed1999

Enhanced myeloid specificity of CD117 compared with CD13 and CD33.

The c-kit proto-oncogene encodes a 145 kd tyrosine kinase transmembrane receptor, which plays a key role in haemopoiesis. The c-kit has been classified as CD117 and is especially useful in the differential diagnosis of acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL). We analysed 104 consecutive cases (55 AML, 23 B-cell lineage ALL, three T-cell ALL, 11 blast crisis of chronic myeloproliferative disorders and 12 cases of myelodysplastic syndromes with more than 10% of blasts) referred to our Hospital for immunophenotypic diagnosis and compared the expression pattern of CD13, CD33 and CD117 using the same fluorochrome (phycoerythrin-PE). The recommendations of the EGIL group were followed in order to establish lineage involvement of the blastic population. The threshold used to assign positivity for CD117 was 10%. Bcr/abl, TEL/AML-1 and MLL rearrangements were assessed by molecular methods. CD117 expression was detected in 91% of AML and MDS. All the negative cases corresponded to acute monocytic leukemias. The calculated specificity for myeloid involvement was 0.86 for CD117, 0.36 for CD13 and 0.44 for CD33 (P < 0.005). CD117 was also positive in four cases of ALL. None of these cases showed bcr/abl or MLL rearrangements. In the light of these findings, CD117 expression should yield a higher score, at least one point, in the system currently applied for the diagnosis of biphenotypic acute leukemias (BAL) as its myeloid specificity is greater than that of CD13 and CD33. Moreover, its absence in AML could identify two subgroups of M5b cases. The coexpression of CD117 with cytoplasmic CD79a is often associated with CD7 reactivity, suggesting a stem cell disorder. CD117 should be included on a routine basis for the immunophenotypic diagnosis of acute leukemias.

Acute Disease↗
PubMed1998

Rapid and simple immunophenotypic characterization of lymphocytes using a new test.

BACKGROUND AND OBJECTIVE: In this paper, we report our experience of lymphocyte phenotyping of a series of 108 consecutive samples using a simple flow cytometry test (Lymphogram). The kit consists of a combination of 5 different markers conjugated with three fluorochromes (CD8-FITC, CD19-FITC, CD56-PE, CD3-PE, CD4-PECy5) in the same tube. This allows identification of different T-cells, NK subpopulations and B lymphocytes. DESIGN AND METHODS: The samples were divided into three groups: samples with absolute lymphocytosis (> 5 x 10(9)/L) (n = 50), samples with relative lymphocytosis (> 50%) (n = 24) and other categories for which a lymphocyte immunophenotype was required (T-cell lymphoma and estimation of blood involvement in chronic lymphoproliferative disorders (CLPD) (n = 34). When CD19+ cells exceeded the normal range or there was a suspicion of CLPD without B-cell lymphopenia, clonality was investigated by means of light chain restriction analysis. RESULTS: In the first group, 29 samples were abnormal (10 CLPD, 3 polyclonal B-cell lymphocytosis, 13 inversions of the CD4/CD8 ratio and 3 cases with CD4 lymphocytosis) and 21 samples were regarded as normal. In the second group 7 samples showed abnormalities (2 CLPD, 3 inverted CD4/CD8 ratios and 2 with a relative increase in CD4 cells). In one sample from the third group B-cell clonality without lymphocytosis was detected whereas in 18 samples a polyclonal pattern was observed. The presence of B-cell lymphopenia precluded further clonality study in 13 samples. INTERPRETATION AND CONCLUSIONS: Lymphogram associated with clonality analysis is a rapid, easy and cheap method of assessing lymphocyte phenotypes in the majority of clinically relevant situations.

Antigens, CD↗
PubMed1998

Serum transferrin receptor in polycythemia.

We measured serum transferrin receptor (sTfR) levels in 22 patients with polycythemia vera and in 26 cases of secondary polycythemia. In our study, raised sTfR levels in both polycythemia groups were related to iron deficiency.

Adult↗
PubMed1998

The role of serum transferrin receptor in the diagnosis of iron deficiency.

BACKGROUND AND OBJECTIVE: Iron deficiency anemia (IDA) is often associated with inflammatory disorders. The most conventional parameters of iron metabolism are therefore affected, making the evaluation of iron status difficult. Serum transferrin receptor (sTfR) levels are raised in iron deficiency but are not influenced by inflammatory changes. The aim of this study was to investigate the role of sTfR in differentiating IDA with inflammatory features. DESIGN AND METHODS: A diagnostic study of sTfR measured by immunoassay was carried out in IDA and anemia of chronic disorders (ACD). The cut-off points of sTfR and the ratio of sTfR/serum ferritin, which were obtained after comparing IDA and ACD, were applied to a group of 64 patients with mixed iron patterns (MIX) (16 with ACD and 48 with IDA). RESULTS: The best cut-off point of sTfR between IDA and ACD was 4.7 mg/L. Applying this cut-off to the MIX group, an efficiency of 87% was obtained (sensitivity 92% and specificity 81%). This level of sTfR correctly classified 53 out of 64 cases of the MIX group (83%). Using the ratio of sTfRx 100/serum ferritin, the best cut-off point was 8 (efficiency 100%), which correctly classified 62 out of 64 cases of the MIX group (97%). INTERPRETATION AND CONCLUSIONS: This study demonstrates that sTfR in conjunction with other iron parameters is very useful in iron deficiency evaluation, especially in hospital practice. Iron treatment should be considered in patients with mixed patterns of iron status, in which the diagnosis of IDA versus ACD is difficult, when the levels of sTfR exceed the cut-off point.

Anemia↗
PubMed1997

Vitamin E serum levels in patients with leukemia, lymphoma and myeloma.

The serum alpha-tocopherol levels were determined in a group of 182 patients with hematological neoplasms: 87 lymphoid or myeloid leukemias, 65 lymphomas and 30 myelomas. The levels did not differ from those of controls, when compared either globally or for diagnosis. Low alpha-tocopherol serum levels were observed in 6 patients (3.3%).

Adolescent↗
PubMed1996

Differentiation of Saccharomyces cerevisiae strains isolated from fermenting musts according to their karyotype patterns.

Pulsed field electrophoresis is a suitable technique for differentiation of Saccharomyces cerevisiae strains. In this work, karyotype analysis was used to study the ecology of the wild S. Cerevisiae flora in musts in fermentation in the A.C. (Appellation Controlee) area of Valdepeñas (Spain). In order to do this, 392 colonies isolated from different vats in different cellars, where dry yeast was never used to make wines, were submitted to the Countour Homogeneous Electric Field (CHEF) technique. Each of the resulting CHEF profiles was subjected to Cluster Analysis and four main karyotypes were found in this viticultural area.

Cluster Analysis↗
PubMed1990

The deoxyuridine suppression test in peripheral lymphocytes.

The effects of different deoxyuridine (dU) concentrations on lymphocytes stimulated with phytohemagglutinin (PHA) were studied for use in a lymphocyte dU suppression test (L-dUST). High concentrations of dU were necessary to overcome the unspecific spontaneous pattern of folate deficiency, dU suppression tests with cells of bone marrow (BM-dUST) and with lymphocytes were carried out in 15 patients with vitamin B-12 deficiency, in 12 with folate deficiency, and in 10 with other pathological conditions. L-dUST was also carried out in 15 healthy reference controls. The BM-dUST was able to distinguish patients with vitamin B-12 or folate acid deficiencies from those without, while the L-dUST was unable to do so in most cases. L-dUST does not, therefore, appear to be a reliable method for the diagnosis of megaloblastic changes.

Bone Marrow↗
PubMedDate not supplied

Serum erythropoietin and erythroid activity in vitamin B12 deficiency.

We studied erythropoiesis in 31 patients with vitamin B12 deficiency by measuring serum erythropoietin (s-Epo), serum transferrin receptor (s-TfR, taken as an index of total erythroid activity), reticulocyte count, and the reticulocyte maturation index (RMI). s-Epo and s-TfR were measured with commercial immunoassays, whereas reticulocyte count and RMI were determined by flow cytometry. s-Epo (123 +/- 196 U/L) and s-TfR (4.1 +/- 2 mg/L) levels were increased in patients with vitamin B12 deficiency. The absolute reticulocyte counts were decreased (29 +/- 18 x 10(9)/L) with a relative increase in the most immature fractions (RMI: 29.6 +/- 18%). A significant negative relationship was found between s-Epo and Hb level (r = -0.65, p < 0.0001). On the average, however, s-Epo was inappropriately low for the degree of anemia, since the observed/predicted (O/P) s-Epo ratio was 0.80 +/- 0.28 in vitamin B12 deficiency vs 1.00 +/- 0.16 in a group of patients with iron deficiency anemia. It is concluded that at least a portion of patients with vitamin B12 deficiency have serum erythropoietin levels that are inappropriately low for the degree of anemia.

Adolescent↗