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D Gallardo

Publications and source records attributed to D Gallardo.

At least 19 recordsLinked to original sources
PubMed2006

New p53 related genes in human tumors: significant downregulation in colon and lung carcinomas.

Human epithelial tumors need to accumulate multiple genetic alterations to form invasive carcinomas. These genetic alterations are related with growth factor receptors, cell signalling, the cell cycle and cell invasiveness. Importantly, cells need to avoid senescence and become immortalized for this process. Recently, five genes: RPS6KA6, HDAC4, KIAA0828, TCP1 and Tip60, which modulate p53-dependent function and avoid senescence were identified in a large-scale RNA interference screen. Twenty colon, 20 prostate and 20 lung carcinomas were studied to investigate whether these genes might be related with human tumors. RNA was extracted from both normal and tumor tissue from each patient. Real-time RT-PCR was performed using TaqMan probes corresponding to the RPS6KA6, HDAC4, KIAA0828, TCP1, Tip60 and p53 genes. In colon carcinomas, the RPS6KA6, HDAC4, KIAA0828 and Tip60 genes were downregulated in tumor tissue as compared with normal tissue (P < 0.001 for all genes). In lung carcinomas, HDAC4, KIAA0820 and Tip60 were downregulated (P < 0.01, P < 0.001 and P < 0.001 respectively). Whereas no significant differences were observed in prostate carcinomas, striking downregulation of the RPS6KA6 and KIAA0828 genes was observed in colon carcinomas and KIAA0828 in a subset of lung carcinomas. mRNA expression of these genes may control p53 function as well as the ras-MAPK pathway, methylation and transcriptional cellular programs. These results could unravel a novel set of regulatory suppressor genes involved in human colon and lung tumors.

Chaperonin Containing TCP-1↗
PubMed2003

Association study between corticotrophin-releasing hormone genomic region (8q13) and rheumatoid arthritis in the Spanish population.

OBJECTIVE: To investigate whether the corticotrophin-releasing hormone (CRH) genomic region confers genetic susceptibility to rheumatoid arthritis (RA) in the Spanish population. METHODS: DNA was obtained from 121 simplex RA families and 101 healthy controls, all from Spanish origin. Two microsatellites, CRHRA1 and CRHRA2, located 25 and 20 kb downstream respectively from the CRH gene were examined using a new multiplex design. Linkage disequilibrium (LD) between the markers was assessed and association studies were carried out using the transmission disequilibrium test (TDT) implemented in TRANSMIT. RESULTS: Both markers are in Hardy-Weinberg equilibrium and there is significant LD between them in the Spanish population. Neither the polymorphic alleles of CRHRA1 and CRHRA2 markers nor their resulting haplotypes were significantly associated to RA. The associated haplotype in the UK population (CRHRA1*10; CRHRA2*14) was undertransmitted in RA patients (12 obs vs 17.43 exp), although the difference is not statistically significant (P > 0.05). CONCLUSIONS: This is the first follow-up study of the association between the CRH genomic region and RA and suggests that the CRH gene may not be involved in the pathogenesis of RA in the Spanish population. Further studies in other populations will help untangle the real contribution of this genomic region to the susceptibility to RA.

Arthritis, Rheumatoid↗
PubMed2003

Richter's syndrome after allogeneic stem cell transplantation for chronic lymphocytic leukaemia successfully treated by withdrawal of immunosuppression, and donor lymphocyte infusion.

Development of high-grade non-Hodgkin's lymphoma is a possible complication of chronic lymphocytic leukaemia/small lymphocytic lymphoma, known as Richter's syndrome (RS). Treatment for RS includes systemic chemotherapy and, recently, allogeneic stem cell transplantation (SCT). We describe a patient with B-chronic lymphocytic leukaemia who developed RS 4 months after allogeneic SCT from an HLA-identical sibling. The RS presented with systemic symptoms, lymphadenopathy, pancytopenia and serum lactate dehydrogenase elevation. The patient was treated with immunosuppressive drug withdrawal and a donor lymphocyte infusion (DLI) of 1 x 10(7) CD3/kg, leading to the disappearance of all symptoms and the attainment of complete donor chimerism. After 18 months of the therapeutic DLI, the patient continues in complete remission.

Erythrocytes↗
PubMed2002

Frequency of HLA-DPB1 disparities detected by reference strand-mediated conformation analysis in HLA-A, -B, and -DRB1 matched siblings.

The role of HLA-DPB1 as transplantation antigen is controversial. The frequency and relevance of HLA-DPB1 mismatch in hematopoietic stem cell transplantation are unknown. To ascertain the rate of HLA-DBP1 mismatch in siblings that had been matched for HLA-A, -B, and -DRB1, reference strand mediated conformation analysis (RSCA) a high resolution HLA typing method was used. Locus-specific primers were used to amplify the HLA-DPB1 locus. The PCR product was then hybridized with two fluorescein-labeled references and the duplexes were analyzed after electrophoresis in a short polyacrylamide gel. Among the 113 pairs of individuals tested, six HLA-DPB1 mismatches were identified, which corresponds to a frequency of 5.31 % (95% confidence interval 3.20%-7.42 %).

Electrophoresis, Polyacrylamide Gel↗
PubMed2001

Do corticosteroids add any benefit to standard GVHD prophylaxis in allogeneic BMT?

In a retrospective study, we compared 15 patients who received cyclosporine (CsA), methotrexate (MTX) and prednisone (PDN) and 15 patients who received CsA-MTX for GVHD prophylaxis after allogeneic BMT (HLA-identical sibling (n = 22), related one HLA mismatch (n = 1), unrelated matched donors (n = 6), unrelated one HLA mismatch (n = 1)). The primary objectives of this study were to compare the incidence of GVHD and post-transplantation complications. Secondary objectives were to compare relapse rate, transplant-related mortality and overall survival. The incidence of acute GVHD grade III-IV was similar between the two groups (P = 0.66), as was the incidence of chronic GVHD (P = 0.67). Incidence of arterial hypertension was significantly higher in patients who received prophylactic PDN, (P = 0.03) and more insulin treatment was required in this group (P = 0.003). We observed no differences in the incidence of infections or upper digestive tract bleeding. Musculoskeletal complications appeared earlier in the group which received PDN. With a median follow-up of 4.4 years, patients in the CsA-MTX group had better overall survival, 46.7% vs 13.3% (P = 0.026). Relapse was a more frequent cause of death in the CsA-MTX group, whereas procedure-related mortality was more frequent in the CsA-MTX-PDN group (P = 0.013). These results suggest that prophylactic prednisone when combined with cyclosporine and methotrexate adds no benefit in acute or chronic GVHD prevention and may increase the morbidity of allogeneic transplantation. Corticosteroids may be reserved for GVHD treatment.

Adolescent↗
PubMed2001

Individually adjusted prophylactic donor lymphocyte infusions after CD34-selected allogeneic peripheral blood stem cell transplantation.

T cell depletion of the graft increases graft failure and relapse rate in allogeneic PBSC transplantation. Delayed lymphocyte add-back after T cell-depleted transplants might prevent these complications. We present 22 consecutive allogeneic PBSC transplants from related histocompatible donors with positive selection of CD34+ cells. Recipients received prophylactic donor lymphocyte infusions (DLI) depending on their risk of relapse and of developing GVHD. Patients were considered at high risk of relapse with AML > first CR, ALL > second CR, and CML in accelerated or blastic phase. Patients were considered at high risk of developing GVHD if older than 35 years, or with a donor sensitized through previous pregnancy or blood transfusion. Patients at high risk of relapse and low risk of GVHD were scheduled to receive three DLI. Patients at low risk of relapse and high risk of GVHD did not receive DLI. The remaining patients were scheduled to receive two DLI. The DLI were administered on days +28 (2 x 10(5)/kg), +60 (2 x 10(5)/kg) and +90 (2 x 10(6)/kg) after transplant. G-CSF mobilized peripheral stem cells from healthy donors were positively selected by an immunomagnetic method. The mean CD34+ cells and CD3+ cells infused were 4.4 x 10(6)(range 1.9-10.6) and 0.085 x 10(5) (range 0.01-0.67). Cyclosporin A was given to prevent GVHD. All the patients engrafted. Twenty-two prophylactic DLI were performed in 12 patients: seven developed acute GVHD (one case grade III-IV) and none presented pancytopenia. At a mean follow-up of 585 days (range 89-1103), 14 patients were alive in CR, one patient was alive in relapse, four patients had died of relapse and three had died of transplant-related complication. Individually adjusted prophylactic DLI at the doses we used with an escalating schedule allowed an acceptable GVHD rate and a good engraftment of donor hematopoiesis.

Adolescent↗
PubMed2001

Disparity for the minor histocompatibility antigen HA-1 is associated with an increased risk of acute graft-versus-host disease (GvHD) but it does not affect chronic GvHD incidence, disease-free survival or overall survival after allogeneic human leucocyte antigen-identical sibling donor transplantation.

Disparity for the minor histocompatibility antigen HA-1 between patient and donor has been associated with an increased risk of acute graft-versus-host disease (GvHD) after allogeneic human leucocyte antigen (HLA)-identical sibling donor stem cell transplantation (SCT). However, no data concerning the impact of such disparity on chronic GvHD, relapse or overall survival are available. A retrospective multicentre study was performed on 215 HLA-A2-positive patients who received an HLA-identical sibling SCT, in order to determine the differences in acute and chronic GvHD incidence on the basis of the presence or absence of the HA-1 antigen mismatch. Disease-free survival and overall survival were also analysed. We detected 34 patient-donor pairs mismatched for HA-1 antigen (15.8%). Grades II-IV acute GvHD occurred in 51.6% of the HA-1-mismatched pairs compared with 37.1% of the non-mismatched. The multivariate logistic regression model showed statistical significance (P: 0.035, OR: 2.96, 95% CI: 1.07-8.14). No differences were observed between the two groups for grades III-IV acute GvHD, chronic GvHD, disease-free survival or overall survival. These results confirmed the association between HA-1 mismatch and risk of mild acute GvHD, but HA-1 mismatch was not associated with an increased incidence of chronic GvHD and did not affect relapse or overall survival.

Acute Disease↗
PubMed2001

Rapid hemophilia A molecular diagnosis by a simple DNA sequencing procedure: identification of 14 novel mutations.

We here describe a simple, efficient DNA sequencing procedure for hemophilia A molecular diagnosis. In severe patients we first test for the presence of factor VIII gene intron 22 inversion using a recently described single-tube PCR method. In moderate, mild, or inversion-negative severe patients we systematically sequence the promoter, all exons and splice junctions of factor VIII gene. Specially designed primers allow amplification of 23 PCR products under the same salt conditions and thermocycling parameters. The whole sequencing procedure, from blood extraction to mutation identification, can be readily done within 42 h when using regular instruments or in just 14 h when using a high-throughput sequencer. Thus, this is a versatile and cost-effective strategy with little hands-on time requirements. Since its implementation we have identified mutations in 45/46 hemophilia A patients, 14 of which are novel. Once the genetic defect has been identified, accurate genetic counseling is then easily performed.

Amino Acid Substitution↗
PubMed2000

Genomic typing of minor histocompatibility antigen HA-1 by reference strand mediated conformation analysis (RSCA).

Disparities in minor histocompatibility antigen (mHAg) HA-1 are involved in the development of acute graft-versus-host disease (GvHD) in adult recipient after HLA-identical sibling donor hematopoietic stem cell transplantation. The mHAg HA-1 is an HLA-A*0201-restricted nonapeptide, which derives from the cleavage of a protein encoded at chromosome 19. The sequence analysis of HA-1 cDNA identified two alleles, termed HA-1H and HA-1R, which differ in only two nucleotides at 3' end of exon A, at positions 500 and 504. DNA-based methods for HA-1 typing were developed in 1998, using polymerase chain reaction with sequence-specific primers (PCR-SSP) and restriction fragment length polymorphism (PCR-RFLP). Here, we report the usefulness of reference strand mediated conformation analysis (RSCA), which was developed for mutation detection and typing of polymorphic loci, to discriminate between the two HA-1 alleles. We performed genomic typing of HA-1 locus in 203 HLA-A*0201-positive samples using RSCA and we confirmed these results by PCR-SSP. The results demonstrate the high reproducibility of this method and their strong correlation with the results obtained by PCR-SSP (99%). Only two samples showed disparity between the RSCA typing and the PCR-SSP. Direct sequencing of these samples confirmed that the correct allele assignment was that obtained by the RSCA typing. Furthermore, HA-1- RSCA-based typing provides additional information about the intronic structure of both alleles. With this approach, we describe the almost constant presence (99.2%) of a 5-bp deletion at intronic position 214-218 associated to the HA-1H allele, previously unidentified. We conclude that HA-1 genomic typing by RSCA is easy to perform and that could be used as a routine typing method.

Alleles↗
PubMed2000

HLA-B44 subtyping in the Catalan population using reference strand mediated conformation analysis. Implications for the selection of unrelated bone marrow donors.

Cytotoxic T lymphocytes (CTLs) reactive against the disparity between HLA-B*4402 and HLA-B*4403 have been reported after unrelated donor bone marrow transplantation. These CTLs have been associated with acute graft-versus-host disease and graft rejection. This study describes the HLA-B44-subtyping in the Catalan population using reference-strand mediated conformation analysis. It has been performed on 297 unrelated HLA-B44+ cord blood units from the Barcelona Cord Blood Bank (Barcelona, Spain). We have found a predominance of HLA-B*4403 (66.04%) over HLA-B*4402 (33.02%), whereas the predominant HLA-B44 allele in Northern Europe and the United States is HLA-B*4402. This inverted proportion between HLA-B44 subtypes in Mediterranean populations compared with other Caucasian populations suggests that HLA-B44 subtyping should be performed when an HLA-B44+ unrelated donor marrow is identified.

Alleles↗
PubMed2000

Factor IX gene sequencing by a simple and sensitive 15-hour procedure for haemophilia B diagnosis: identification of two novel mutations.

We have developed a simple, sensitive and cost-effective direct DNA sequencing procedure for the molecular diagnosis of haemophilia B. All factor IX gene essential regions were amplified under identical thermocycling parameters allowing mutation identification in less than 15 h from blood sample collection. Identical results in terms of accuracy and speed were obtained when using a single hair as the source of DNA. Using this approach, we have found mutations in 10 out of 10 haemophilia B patients, two of which are novel (P287T and S123C). Very suitable for individual studies, this procedure can be easily scaled up for higher throughput.

Electronic Data Processing↗
PubMed2000

Mitoxantrone, etoposide, carboplatinum and ara-C combination therapy (MECA) in refractory and relapsed acute leukemia.

The present study was undertaken to assess the feasibility, toxicity and antileukemic activity of sequential chemotherapy including mitoxantrone, etoposide, carboplatin and intermediate-dose cytarabine in adult patients with refractory and relapsed acute myelogenous (AML) or lymphoid (ALL) leukemia. Fifty-one patients with poor-risk AML and ALL received 64 courses of MECA therapy. The overall response in the entire group was 51% (43% complete remission). The stage of the disease (relapsed or primarily refractory) and the age of the patients did not strongly affect the response rate. MECA therapy was more effective in ALL than in AML, and in those patients who presented at salvage treatment with a bone marrow infiltration lower than 25% blasts. Hematological and extra-hematological toxicities were tolerable and there were 6 deaths related to the treatment (11%). The incidence of documented infectious episodes was 71%. MECA therapy is a safe treatment and has a high antileukemic activity in relapsed and primarily refractory AML or ALL.

Actuarial Analysis↗
PubMed2000

Follow-up of chimerism status after allogeneic HLA-mismatched stem cell transplantation by detection of non-shared HLA alleles.

BACKGROUND AND OBJECTIVES: Chimerism studies after allogeneic transplantation are usually performed using cytogenetic analysis, PCR-VNTR or PCR-STR. Here, we report an alternative method for following the chimerism status after an HLA-mismatched stem cell transplantation (SCT), detecting the presence of non-shared HLA alleles by reference-strand mediated conformation analysis (RSCA). DESIGN AND METHODS: We tested this new approach on allogeneic related haploidentical SCT, unrelated cord blood transplantation, and HLA-mismatched unrelated donor SCT. The quantification of the chimerism was performed by laser detection of fluorescent-labeled primers on an automated DNA sequencer. RESULTS: In all cases this technique was able to detect mixed chimeras. The technique detected above 5% of residual cells when the analysis was based on HLA-class I and above 3% for HLA-class II. This sensitivity is similar to that of the PCR-VNTR analysis. INTERPRETATION AND CONCLUSIONS: This method avoids the need to search for an informative locus (which is essential for PCR-VNTR or -STR). Moreover, we did not find the phenomenon of preferential amplification that is observed with most VNTR, thus avoiding the need for construction of standard curves to quantify mixed chimeras. We conclude that the detection of the non-shared HLA alleles by RSCA is a useful approach for chimerism follow-up after HLA-mismatched SCT.

Alleles↗