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Antonio Martínez

Publications and source records attributed to Antonio Martínez.

At least 19 recordsLinked to original sources
PubMed2006

Transcriptional profiling of hematologic malignancies with a low-density DNA microarray.

BACKGROUND: High-density microarrays are powerful tools for expression analysis of thousands of genes simultaneously; however, experience with low-density microarrays in gene expression studies has been limited. METHODS: We developed an optimized procedure for gene expression analysis based on a microarray containing 538 oligonucleotides and used this procedure to analyze neoplastic cell lines and whole-blood samples from healthy individuals and patients with different hematologic neoplasias. Hierarchical clustering and the Welch t-test with adjusted P values were used for data analysis. RESULTS: This procedure detects 0.2 fmol of mRNA and generates a linear response of 2 orders of magnitude, with CV values of <20% for hybridization and label replicates. We found statistically significant differences between Jurkat and U937 cell lines, between blood samples from 15 healthy donors and 59 chronic lymphocytic leukemia (CLL) samples, and between 6 acute myeloid leukemia patients and 4 myelodysplastic syndrome patients. A classification system constructed from the expression data predicted healthy or CLL status from a whole-blood sample with a 97% success rate. CONCLUSION: Transcriptional profiling of whole-blood samples was carried out without any cellular or sample manipulation before RNA extraction. This gene expression analysis procedure uncovered statistically significant differences associated with different hematologic neoplasias and made possible the construction of a classification system that predicts the healthy or CLL status from a whole-blood sample.

Acute Disease↗
PubMed2006

A design framework to model retinas.

Neuro-engineering is providing biomedical engineers with technology to interface the nervous system, which is useful to create prosthetic devices to palliate sensorial or motor disabilities. Motivated by the success of cochlear implants for deaf patients, we are now facing the challenge of creating a prosthetic visual system for the blind. An artificial retina whose response to stimuli can be matched to biological ones is required. To make easier the task of modeling, tuning and testing these retinal models, we have created a software tool that allows flexible and parametric definition and testing of retina-like models. The program can be fed with a variety of video or image sources, and the results can be easily compared to biological recordings of retinal ganglionar activity in response to the same stimuli. This tool can be useful, not only for this prosthetic purpose, but for any other research involving bio-inspired image processing with a neuromorphic output.

Artificial Organs↗
PubMed2006

Biotransformations of ent-18-acetoxy-6-ketomanoyl oxides epimers at C-13 with filamentous fungi.

Two ent-18-acetoxy-6-oxomanoyl oxides, epimers at C-13, have been prepared from ent-6alpha,8alpha,18-trihydroxylabda-13(16),14-diene (andalusol), isolated from Sideritis foetens, by means of several chemical pathways and a regioselective acylation with Candida cylindracea lipase (CCL). Biotransformation of these 13-epimeric ent-manoyl oxides by Fusarium moniliforme and Neurospora crassa produced mainly ent-1beta- or ent-11alpha-hydroxylations, as well as their deacetylated derivatives, in both epimers. In addition, with the 13-epi substrate N. crassa originated other minor hydroxylations by the ent-alpha face at C-1 or at C-12, whereas an ent-11beta-hydroxyl group, probably originated by reduction of an 11-oxo derivative also isolated, was achieved with the 13-normal substrate.

Biotransformation↗
PubMed2006

Identification of chitotriosidase isoforms in plasma of Gaucher disease patients by two dimensional gel electrophoresis.

Chitotriosidase protein (ChT) is the most important biochemical marker described for Gaucher disease (GD). ChT activity is increased several hundred-fold in plasma of GD patients and shows a strong positive correlation with the severity of the disease. However, a recessively inherited enzyme deficiency, with an incidence of about 6% in the Caucasian population, means that not all patients with GD can be monitored by measuring ChT activity. Applying two-dimensional gel electrophoresis (2-DE) technology this study describes the localization and identification of five ChT isoforms in 2-DE images obtained from plasma of GD patients. All these isoforms were unequivocally identified using MALDI-TOF mass spectrometry (MS) and validated by western blot analysis. The features of each ChT isoform separated by 2-DE in plasma from GD patients homozygous for the wild-type ChT allele, carriers of one defective allele and patients homozygous for the mutant allele are presented. We also show the correlation between each ChT isoform and the plasma ChT enzymatic activity of the GD patients sampled in this study.

Blotting, Western↗
PubMed2006

Prognostic value of RT-PCR tyrosinase detection in peripheral blood of melanoma patients.

Malignant melanoma (MM) prognosis has been related to tumour thickness and clinical stage and metastasis risk has been associated with presence of tumour cells in peripheral blood. The aim of this study was to determine the relationship between presence of tyrosinase in peripheral blood of MM patients and their clinical prognosis. Blood samples from 58 MM patients (stage I-IV) were analysed, using RT-PCR assay to detect tyrosinase mRNA. The results showed that positive RT-PCR assay for tyrosinase were significantly associated with clinical status and tumour thickness. After a median follow-up of 24 months, RT-PCR results were found to be significant correlated with recurrence (p<0.05) and clinical stage III (p<0.05). Separate analysis of stage III tumours to determine the prognostic value of tyrosinase presence in peripheral blood showed an overall 24-month survival rate of 70% in the RT-PCR negative group versus 10% in the positive group (p<0.02). These results suggest that detection of circulating melanoma cells may be especially relevant in stage III patients, in whom RT-PCR positivity defines a subpopulation at high risk of recurrence.

Adult↗
PubMed2006

A comparison of the effects of 0.005% latanoprost and fixed combination dorzolamide/timolol on retrobulbar haemodynamics in previously untreated glaucoma patients.

OBJECTIVE: To assess the effects of dorzolamide/timolol fixed combination (DTFC) and latanoprost 0.005% on the retrobulbar haemodynamics and intraocular pressure (IOP) of open-angle glaucoma patients. METHODS: 22 consecutive subjects with newly diagnosed, open-angle glaucoma were included in this prospective, examiner masked, randomized, crossover study. The patients were randomized into two different arms. Peak systolic velocity (PSV), end-diastolic velocity (EDV), Pourcelot's resistance index (RI) and intraocular pressure (IOP) were determined at baseline and after 1 month of medical treatment with DTFC or latanoprost 0.005% in both groups. A 4-week washout period, without medical treatment, between study arms was carried out. Primary efficacy variables were the PSV, EDV and RI in the ophthalmic artery (OA) and short posterior ciliary artery (SPCA) and intraocular pressure (IOP). Inter- and intra-group comparisons were performed with a one-way ANOVA test and two-tailed paired Student's t-test respectively. RESULTS: Intraocular pressure (IOP) and colour Doppler imaging (CDI) measurements were similar at baseline. Compared to baseline and washout measurements, only the fixed combination dorzolamide/timolol significantly increased the EDV in the OA and in the SPCA, p = 0.00012 and p = 0.00012, respectively and decreased the resistance index in the ophthalmic and short posterior ciliary arteries, p = 0.00011 and p = 0.00031, respectively. There were no statistically significant differences in the IOP lowering effect of either treatment. CONCLUSION: Over a treatment period of 1 month, only the fixed combination dorzolamide/timolol seems to have a vascular effect on retrobulbar vessels. Further research is necessary to confirm these results.

Aged↗
PubMed2005

Transformation of organoarsenical species by the microflora of freshwater crayfish.

A study of the transformation of arsenic species by the microflora of the freshwater crayfish Procambarus clarkii was carried out. The study of the degradation of AB (arsenobetaine) was performed in aerobic conditions in two culture media (tryptic soy broth and saline medium) at two temperatures (30 and 8 degrees C). The microflora transformed AB into TMAO (trimethylarsine oxide), DMA (dimethylarsinate), MA (methylarsonate), and an unidentified compound (U1). The quickest transformations were carried out by microflora from hepatopancreas incubated in saline medium at 30 degrees C. The individualized study of other arsenic species [AC (arsenocholine), TETRA (tetramethylarsonium ion), TMAO, DMA, and MA] was also performed in saline medium. The only transformation observed was of AC into AB. The bacteria possibly responsible for AB degradation were isolated, identified by phenotypic and genotypic methods, and individually assayed for AB transformation. Only isolates allocated to the species Pseudomonas putida were able to metabolize AB.

Animals↗
PubMed2005

A randomized double-blind trial of iseganan in prevention of ventilator-associated pneumonia.

RATIONALE: Iseganan, an antimicrobial peptide, is active against aerobic and anaerobic gram-positive and gram-negative bacteria as well as fungi and yeasts. The drug has shown little resistance in vitro and to be safe and well tolerated in 800 patients with cancer treated for up to 6 wk. OBJECTIVES: To determine the efficacy of iseganan for the prevention of ventilator-associated pneumonia (VAP). METHODS: Mechanically ventilated patients in the United States and Europe were randomized to oral topical iseganan or placebo (1:1) and treated six times per day while intubated for up to 14 d. Patients were eligible if randomized within 24 h of intubation and estimated to survive and remain mechanically ventilated for 48 h or more. The primary efficacy endpoint of the study was VAP measured among survivors at Day 14. MEASUREMENTS AND MAIN RESULTS: A total of 709 patients were randomized and received at least one dose of study drug. The two groups were comparable at baseline except iseganan-treated patients were, on average, 3 yr older. The rate of VAP among survivors at Day 14 was 16% (45/282) in patients treated with iseganan and 20% (57/284) in those treated with placebo (p = 0.145). Mortality at Day 14 was 22.1% (80/362) in the iseganan group compared with 18.2% (63/347) in the placebo group (p = 0.206). No pattern of excess adverse events in the iseganan group compared with placebo was observed. CONCLUSIONS: Iseganan is not effective in improving outcome in patients on prolonged mechanical ventilation.

Administration, Oral↗
PubMed2005

Targeting the extracellular domain of fibroblast growth factor receptor 3 with human single-chain Fv antibodies inhibits bladder carcinoma cell line proliferation.

PURPOSE: Previous gene expression studies have shown that fibroblast growth factor receptor 3 (FGFR3) is overexpressed in early stages of bladder cancer. To study the potential use of therapeutic antibodies against FGFR3, we have produced a collection of human single-chain Fv (scFv) antibody fragments by using phage display libraries. EXPERIMENTAL DESIGN: Two "naïve" semi-synthetic human scFv libraries were used to select antibodies against the extracellular domain of FGFR3alpha(IIIc). The reactivity of the selected scFvs with a recombinant FGFR3 was characterized by an enzyme immunoassay and surface plasmon resonance analysis and with RT112 bladder carcinoma cells by a fluorescence-activated cell sorter. The capacity of the selected scFvs to block RT112 cell proliferation was determined. RESULTS: We have isolated six human scFv antibody fragments directed against FGFR3. These human scFvs specifically bound FGFR3, but not the homologous molecule FGFR1. Biacore analysis was used to determine the affinity constants, which ranged from 12 to 40 nmol/L. Competition analysis showed that the FGF9 ligand was able to block the binding of two scFvs, 3C and 7D, to FGFR3, whereas FGF1 only blocked 7D. Immunoprecipitation and flow cytometric analysis confirmed the specificity of the antibodies to native membrane FGFR3. Two scFvs, 3C and 7D, gave an strong immunofluorescence staining of RT112 cells. Moreover, they recognized equally well wild-type and mutant FGFR3 containing the activating mutation S249C. Furthermore, they blocked proliferation of RT112 cells in a dose- and FGF-dependent manner. CONCLUSION: Our results suggest that these human anti-FGFR3 scFv antibodies may have potential applications as antitumoral agents in bladder cancer.

Amino Acid Sequence↗
PubMed2005

Reliable low-density DNA array based on allele-specific probes for detection of 118 mutations causing familial hypercholesterolemia.

BACKGROUND: Patients with familial hypercholesterolemia (FH) have a high risk of premature cardiovascular disease (PCVD). Mutations in the LDL receptor (LDLR) gene and the R3500Q mutation in the apolipoprotein B (APOB) gene are known to cause FH, but lack of high-throughput methods makes routine genetic diagnosis difficult. The objective of this work was to develop a DNA array for large-scale identification of mutant LDLR alleles. METHODS: We developed a low-density oligonucleotide microarray to identify 118 DNA sequence variations (117 for the LDLR gene and 1 for the APOB gene). We verified specificity and sensitivity by analyzing 1180 previously sequenced DNA samples, and conducted a blind study screening 407 Spanish patients with a clinical diagnosis of FH. RESULTS: The DNA array confirmed the previous genotyping results in almost all cases. In the blind study, the microarray detected at least 1 mutation in 51% of the patients for whom clinical diagnosis was classified as certain according to Dutch FH-MEDPED criteria; it also identified mutations in 37% of those with a diagnosis of probable/possible FH, thus giving a definite diagnosis. Patients harboring null mutations had shorter PCVD-free survival times and higher relative risk of PCVD than patients with a missense mutation. CONCLUSIONS: The proposed DNA array allows large-scale population screening and provides molecular information regarding mutation type and its correlation with clinical severity of FH, which can be used to develop therapeutic strategies.

Alleles↗
PubMed2005

Fibroblast growth factor receptor 3 is overexpressed in urinary tract carcinomas and modulates the neoplastic cell growth.

PURPOSE: Fibroblast growth factor receptor 3 (FGFR3) mutations have been associated with achondroplastic syndromes and urinary bladder carcinomas. Here we describe changes in FGFR3 mRNA and protein expression in transitional carcinomas and determine the effect of monoclonal antibodies against FGFR3 in RT-112 cell line proliferation. EXPERIMENTAL DESIGN: We used microarray tools to evaluate FGFR3 mRNA expression in 22 urinary bladder carcinomas at different stages (noninvasive pTa, lamina propria invasive pT1, and muscular invasive pT2) and 7 nonneoplastic tissue controls. FGFR3 protein expression was evaluated by Western blotting in 15 different carcinomas and 3 nonneoplastic controls. Two hundred thirty-seven urinary bladder and renal pelvis carcinomas and 21 negative controls were tested on tissue microarrays by immunohistochemistry. The effect on cell proliferation in the RT-112 bladder cancer cell line of monoclonal antibodies against FGFR3 was also evaluated. RESULTS: Overexpression of FGFR3 mRNA was found in pTa and pT1 stage carcinomas (fold change >8) and in pT2 carcinomas (fold change >4). Nonneoplastic urinary bladder samples do not express FGFR3 protein. However, 83% of pTa, 100% of pT1, and 50% of pT2 carcinomas expressed FGFR3 as determined by Western blotting. By immunohistochemistry, FGFR3 was positive in 71.4% of pTa, 72% of pT1, and 49.2% of pT2 cases as well as 61.5% of upper urinary tract carcinomas. Proliferation of the RT-112 cell line was inhibited with monoclonal antibodies against FGFR3. CONCLUSIONS: FGFR3 seems to play an important role in transitional cell carcinoma development. Our results suggest that FGFR3 antagonists could be developed as possible therapeutics for treatment of urinary tract carcinoma.

Antibodies, Monoclonal↗
PubMed2005

Enzyme-catalyzed rearrangement of a diepoxy-germacrane compound into new 7-epi-eudesmane derivatives.

Two new 7-epi-eudesmane derivatives, together with two new germacrane compounds, have been isolated from the microbial-transformation of a (1alpha,10beta),(4beta,5alpha)-diepoxygermacrane using the hydroxylating fungi Rhizopus nigricans. The rearranged skeleton and the stereochemistry of the chiral centers have been determined by means of their spectral data, and the absolute configuration has been confirmed by single-crystal X-ray analyses. A possible mechanism based on an enzyme-catalyzed isomerization to a 1alpha-hydroxy-(4beta,5alpha)-epoxygermacr-9(E)-ene intermediate and a subsequent cyclization process is proposed in order to explain the formation of the 7-epi-eudesmane compounds.

Biotransformation↗
PubMed2005

Changes on bone mineral density after adjuvant treatment in women with non-metastatic breast cancer.

PURPOSE: . Adjuvant therapies have prolonged survival of non-metastatic breast cancer (NMBC) patients, but they also decrease bone mineral density (BMD). We have analyzed the effects of chemotherapy, hormone therapy with tamoxifen or both, on BMD of women with NMBC. PATIENTS AND METHODS: We prospectively included 168 women with NMBC (stage I-III) referred to the Medical Oncology Service of University Hospital of Canary Islands between 1997 and 2001 (55 +/- 12 years; 37% premenopausal; 43 +/- 13 months of follow-up). We measured lumbar and hip BMD (g/cm2) at diagnosis, after chemotherapy and after 12 months of tamoxifen. If a low BMD was detected, women were treated with bisphosphonates. RESULTS: BMD after chemotherapy (n = 83) significantly decreased at lumbar (1.014 +/- 0; 0.995 +/- 0, p = 0.0001), trochanter (0.701 +/- 0; 0.690 +/- 0, p = 0.001), intertrochanter (1.095 +/- 0; 1.078 +/- 0, p = 0.0001) and total hip (0.924 +/- 0; 0.915 +/- 0, p = 0.046) areas. Although 60% of the premenopausal women suffered amenorrhea after chemotherapy, there were not significant differences in BMD between them and women who retained menses. BMD of women who received 12 months of tamoxifen after chemotherapy increased--total hip (0.907 +/- 0; 0.922 +/- 0, p = 0.005) and intertrochanter (1.071 +/- 0; 1.091 +/- 0, p = 0.003)--or remained stable--lumbar, femoral neck, trochanter, and Ward's triangle (n = 39). When tamoxifen was the only adjuvant treatment, BMD after 12 months (n = 22) increased in trochanter area (0.644 +/- 0; 0.663 +/- 0, p = 0.011), and remained stable in all other sites. 50 (30%) patients were treated with bisphosphonates because of osteopenia. CONCLUSION: Women with NMBC are affected by early bone loss after adjuvant chemotherapy. This bone loss is attenuated by one year of tamoxifen treatment.

Amenorrhea↗
PubMed2005

ent-Kauranoid derivatives from Sideritis moorei.

Seven new ent-kauranoid derivatives ent-7alpha,18-dihydroxykaur-16-en-3-one, ent-18-acetoxy-3beta,7alpha-dihydroxykaur-15-en-17-al, ent-3beta-acetoxy-7alpha,18-dihydroxykaur-15-en-17-al, ent-18-acetoxy-3beta,7alpha,17-trihydroxykaur-15-ene, ent-3beta-acetoxy-7alpha,17,18-trihydroxykaur-15-ene, ent-18-acetoxy-3beta,7alpha,17-trihydroxy-15beta,16beta-epoxykaurane and ent-3beta-acetoxy-7alpha,17,18-trihydroxy-15beta,16beta-epoxykaurane have been isolated from Sideritis moorei. The structures of these compounds have been established by spectroscopic means and chemical correlations.

Acetylation↗
PubMed2005

Predictive value of colour Doppler imaging in a prospective study of visual field progression in primary open-angle glaucoma.

PURPOSE: To assess the value of colour Doppler imaging (CDI) of the ophthalmic artery (OA) and short posterior ciliary arteries (SPCAs) in prognosis of disease progression in patients with primary open-angle glaucoma (POAG). METHODS: A total of 49 eyes of 49 patients with POAG were included in a prospective cohort study. At baseline and every 6 months for 36 months, we measured the resistive indices (RIs) of the OA and SPCAs using CDI, visual field examination, intraocular pressure (IOP) and blood pressure measurements. The predictive capacity of the RIs of these vessels was investigated by Cox regression. Receiver operating characteristics curves were plotted for the OA and SPCAs RIs, and predictive values, likelihood ratios and post-test probabilities were calculated. RESULTS: After 36 months, 23 eyes had progressed. In the eyes that progressed, the mean (SD) RI was 0.82 (0.007) for the OA and 0.73 (0.006) for the SPCAs; in the eyes that did not progress the mean RI was 0.70 (0.007) for the OA and 0.63 (0.006) for the SPCAs. The optimal points for the RIs were 0.72 for the OA and 0.65 for the SPCAs. With these cut-off points, the positive post-test probability was 90.5% in the OA. CONCLUSION: In eyes with POAG and elevated IOP, the RIs of the OA or SPCAs may reliably predict visual field progression.

Blood Flow Velocity↗
PubMed2004

Biotransformation of ent-13-epi-manoyl oxides difunctionalized at C-3 and C-12 by filamentous fungi.

Biotransformation of ent-3beta,12alpha-dihydroxy-13-epi-manoyl oxide with Fusarium moniliforme gave the regioselective oxidation of the hydroxyl group at C-3 and the ent-7beta-hydroxylation. The action of Gliocladium roseum in the 3,12-diketoderivative originated monohydroxylations at C-1 and C-7, both by the ent-beta face, while Rhizopus nigricans produced hydroxylation at C-7 or C-18, epoxidation of the double bond, reduction of the keto group at C-3, and combined actions as biohydroxylation at C-2/epoxidation of the double bond and hydroxylation at C-7/reduction of the keto group at C-3. In the ent-3-hydroxy-12-keto epimers, G. roseum originated monohydroxylations at C-1 and C-7 and R. nigricans originated the oxidation at C-3 as a major transformation, epoxidation of double bond and hydroxylation at C-2. Finally, in the ent-3beta-hydroxy epimer R. nigricans also originated minor hydroxylations at C-1, C-6, C-7 and C-20 and F. moniliforme produced an hydroxylation at C-7 and a dihydroxylation at C-7/C-11.

Biotransformation↗
PubMed2004

Diffuse large B-cell lymphomas with plasmablastic differentiation represent a heterogeneous group of disease entities.

Plasmablastic lymphoma was initially described as a variant of diffuse large B-cell lymphoma (DLBCL) involving the oral cavity of HIV+ patients and characterized by immunoblastic morphology and a plasma cell phenotype. However, other lymphomas may exhibit similar morphologic and immunophenotypic features. To determine the significance of plasmablastic differentiation in DLBCL and examine the heterogeneity of lymphomas with these characteristics, we examined 50 DLBCLs with low/absent CD20/CD79a and an immunophenotype indicative of terminal B-cell differentiation (MUM1/CD38/CD138/EMA-positive). We were able to define several distinct subgroups. Twenty-three tumors were classified as plasmablastic lymphoma of the oral mucosa type and showed a monomorphic population of immunoblasts with no or minimal plasmacytic differentiation. Most patients were HIV+ and EBV was positive in 74%. Eleven (48%) cases presented in the oral mucosa, but the remaining presented in other extranodal (39%) or nodal (13%) sites. Sixteen cases were classified as plasmablastic lymphoma with plasmacytic differentiation. These were composed predominantly of immunoblasts and plasmablasts, but in addition exhibited more differentiation to mature plasma cells. Only 33% were HIV+, EBV was detected in 62%, and 44% had nodal presentation. Nine cases, morphologically indistinguishable from the previous group, were secondary extramedullary plasmablastic tumors occurring in patients with prior or synchronous plasma cell neoplasms, classified as multiple myeloma in 7 of the 9. Two additional neoplasms were an HHV-8+ extracavitary variant of primary effusion lymphoma and an ALK+ DLBCL. HHV-8 was examined in 39 additional cases, and was negative in all. In conclusion, DLBCLs with plasmablastic differentiation are a heterogeneous group of neoplasms with different clinicopathological characteristics that may correspond to different entities.

Adult↗