Biomedical subjects

A Martínez

Publications and source records attributed to A Martínez.

At least 19 recordsLinked to original sources

PubMed2007

Involvement of macrophage migration inhibitory factor gene in celiac disease susceptibility.

The MIF gene has been associated with several diseases with inflammatory and autoimmune background, such as ulcerative colitis, rheumatoid arthritis and systemic lupus erythematosus. We aimed at testing the influence of two functional MIF promoter variants in celiac disease (CD) susceptibility. A (CAAT)(5-8) tetranucleotide repeat at position -794 and a single-nucleotide polymorphism at -173G/C were analyzed in the Spanish population (531 patients and 887 healthy controls). chi(2) statistics or Fisher exact test were used for comparisons. The -173C allele significantly increased risk ((CC+GC) vs GG: odds ratio (OR) (95% confidence interval (CI))=1.41 (1.10-1.81); P=0.005), as did carriage of the (CAAT)(7) allele (OR (95% CI)=1.36 (1.02-1.82); P=0.03) and of the haplotype (CAAT)(7)//-173C (OR (95% CI)=1.33 (1.00-1.76); P=0.04). Our data evidence for first time the role of the MIF gene increasing predisposition to CD. A common effect of MIF variants seems to underlie the etiology of these complex conditions.

Celiac Disease↗

PubMed2006

Role of the BRAF mutations in the microsatellite instability genetic pathway in sporadic colorectal cancer.

BACKGROUND AND AIMS: Between 10 and 15% of all cases of colorectal cancer are the result of microsatellite instability (MSI) in the genetic pathway due to an alteration in the DNA repair genes. Tumors with high MSI are characterized by a better prognosis. The BRAF oncogene has been linked to the MSI pathway in tumorogenesis. The objective of this study was to determine whether alterations in BRAF are related to MSI and whether they can result in differences in survival rates. METHODS: The study cohort comprised 351 patients diagnosed with sporadic colorectal cancer. MSI was determined in accordance with the National Cancer Institute's (NCI) recommendations by means of PCR and sequence analyses. Mutational analysis of the BRAF gene was performed by real-time PCR and subsequent sequencing of the altered samples. The methylation pattern of the hMLH1 gene was determined using methylation-specific PCR analyses of bisulfite-treated DNA and the results confirmed by sequencing. RESULTS: Of the patients tested, 6.9% showed high MSI and 3.7% showed a BRAF gene mutation. hMLH1 methylation was observed in 67.2% of the patients with MSI and/or the BRAF alteration. The BRAF mutation was related to the MSI genetic pathway (P < 0.0001) and with hMLH1 methylation. In the analysis of overall survival only MSI had an independent prognostic value for the risk of death. Patients with the BRAF mutation showed a higher risk of death, although this association was found not to be statistically significant. CONCLUSIONS: There is a subgroup of carcinomas which develop via the MSI pathway that carry an alteration of the BRAF gene. This alteration confers a poorer outcome on these patients within the total group of patients with MSI who have a better prognosis. This hypothesis should be further investigated in a larger study population due to the low incidence of BRAF mutations in colorectal cancer.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Intrauterine Neospora caninum inoculation of heifers and cows using contaminated semen with different numbers of tachyzoites.

OBJECTIVE: To investigate the potential of different Neospora caninum tachyzoite doses to infect heifers (experiment 1) and cows (experiment 2) when administered in utero by artificial insemination via contaminated semen. METHODS: In experiment 1, five groups of 5, 7, 8, 9, and 5 cyclic heifers were hormonally synchronized and artificially inseminated with semen containing 0 (A, controls), 10(2) (B), 5 x 10(3) (C), 5 x 10(4) (D), and 5 x 10(5) (E) live N. caninum NC-1 isolate-tachyzoites, respectively. Experimental infection was followed for 100 days. Parasitaemia and specific serum IgG, and interferon-gamma (IFN-gamma) responses were studied. In experiment 2, four groups of 9, 10, 9, and 9 adult multiparous cows with confirmed infertility problems of diverse aethiology were hormonally synchronized and artificially inseminated with semen containing 0 (a, controls), 10(2) (b), 5 x 10(3) (c), and 5 x 10(5) (d) live N. caninum NC-1 isolate-tachyzoites, respectively. Experimental infection was followed for 63 days. Parasitaemia and specific serum IgG responses were studied. RESULTS: In experiment 1, parasitaemia was detected in 1, 2, and 3 heifers from groups B, C, and D, respectively, between 9 and 23 days after insemination. Persistent specific serum antibody responses were detected in 2 and 3 heifers from groups D and E, respectively. Transient specific serum antibody responses were detected in 2, 1 and 1 heifers from groups C, D, and E, respectively. In addition, 1 heifer from group B showed a serum-specific antibody level higher than cut off value at 21 days post-insemination. Heifers seroconverted between 23 and 47 days after insemination. Specific IFN-gamma levels were detected in 1, 4, 6, and 3 heifers from groups B, C, D, and E, respectively, between 9 and 55 days after insemination. Pregnancy rate in the control group (60%) was higher than those observed in inoculated heifers (0-42.9%). Pregnancy rates in inoculated heifers were lower when the tachyzoite dose was increased (B 42.9%, C 12.5%, D 11.1%, and E 0%). In experiment 2, no Neospora DNA in blood nor specific serum IgG to N. caninum were detected in any of the cows studied, except in one cow inoculated with 5 x 10(5) tachyzoites (group d) which showed a relative index x100 (RIPC) values of 9.4, 18.9, and 18.1 at 42, 56, and 63 days after insemination, respectively. CONCLUSIONS: This study provides evidence that the intrauterine infection via contaminated semen using 5 x 10(4) and 5 x 10(5) tachyzoites caused persistent serum-specific antibody responses in some heifers. On the basis of serological data, a dose-response effect was also observed. In addition, N. caninum would be a probable cause of early foetal death in inoculated heifers. In contrast, results obtained in a similar experiment with cows showing confirmed infertility indicate that higher doses, such as of 5 x 10(5) tachyzoites, were necessary to induce seroconversion in at least one animal.

Animals↗

PubMed2006

Autologous bone-marrow mononuclear cell implantation in patients with severe lower limb ischaemia: a comparison of using blood cell separator and Ficoll density gradient centrifugation.

Different studies have provided evidence that implantation of bone-marrow mononuclear cells (BM-MNC) into ischaemic limbs can improve tissue vascularization. Based on these results we performed a pilot study in patients with critical lower limb ischaemia to assess efficacy and safety of implantation of autologous BM-MNC. The amount and efficacy of BM-MNC purified either by an automated method or by a manual procedure were compared. Twelve patients with severe unilateral lower limb ischaemia were entered into this study. They were randomly assigned to be injected with BM-MNC sorted on a blood cell separator or isolated by density gradient on Ficoll-Hypaque. BM-MNC were implanted into the ischaemic legs. Patients were monitored with resting ankle-brachial pressure index (ABI), arterial oxygen saturation (SaO(2)), pain-free walking time and rest pain scale evaluation. The automated and manual methods used for mononuclear cell separation gave results not significantly different. Monitored variables improved in both groups. Improvement of ischaemic condition persisted during 24 weeks follow-up. Limb salvage was achieved in five cases. Our results indicate that BM-MNC implantation into ischaemic limbs is a practical, safe and effective method that may significantly contribute to the management of patients with limb ischaemia. The Ficoll method is a simple and effective procedure for BM-MNC concentration that may be useful, mainly in hospitals without sophisticated facilities.

Aged↗

PubMed2006

Effects of acute hypobaric hypoxia on the nitric oxide system of the rat cerebral cortex: Protective role of nitric oxide inhibitors.

Exposure to hypobaric hypoxia produces neuropsychological disorders. The brain nitrergic system was investigated following hypobaric hypoxia in the presence or absence of nitric oxide synthase (NOS) inhibitors. Adult rats were exposed to a simulated altitude of 8325 m (27,000 ft) for 7 h and killed after 0, 1, 3, 5, and 10 days of recovery. In addition to normobaric controls, three experimental groups were studied: i) subjected to hypobaric hypoxia without inhibitors; ii) subjected to hypobaric hypoxia and treated with 7-nitroindazole; iii) subjected to hypobaric hypoxia and treated with N(omega)-nitro-l-arginine methyl ester (l-NAME). Cerebral cortex was assayed by immunohistochemistry, Western blotting, and enzymatic assays. In animals subjected to hypobaric hypoxia without inhibitors, there was an increase in neuronal nitric oxide synthase (nNOS) immunoreactivity and Ca(2+)-dependent NOS activity from 0 to 1 days of reoxygenation. In these animals, inducible nitric oxide synthase (iNOS) expression and Ca(2+)-independent activity were undetectable, but nitrotyrosine immunoreactivity was found in some neurons. Administration of either inhibitor prevented the increase in nNOS immunoreactivity and enzymatic activity provoked by hypobaric hypoxia. Concomitantly, nitrotyrosine immunoreactivity decreased progressively. In conclusion, activation of the nitrergic system constitutes a cortical response to hypobaric hypoxia and the administration of NOS inhibitors could provide new therapeutic avenues to prevent and/or treat the symptoms produced by hypobaric hypoxia.

Altitude↗

PubMed2006

The Follicular Lymphoma International Prognostic Index (FLIPI) and the histological subtype are the most important factors to predict histological transformation in follicular lymphoma.

BACKGROUND: Histological transformation (HT) is a well-known event in patients with follicular lymphoma (FL) conferring an unfavorable prognosis. The aim of the study was to analyze incidence and risk factors for HT in a large series of FL patients. PATIENTS AND METHODS: 276 patients (median age: 54 years; M139/F137) diagnosed with FL (42% grade 1, 51% 2, 7% 3) in a single institution were studied. Initial treatment consisted of combined chemotherapy in most cases. Median survival was 11.3 years. Main clinic and biological variables were assessed for HT and survival. RESULTS: 30 of 276 patients (11%) presented HT after a median follow-up of 6.5 years, with a risk of 15% and 22% at 10 and at 15 years, respectively. All HT corresponded to diffuse large B-cell lymphoma (DLBCL). Grade 3 histology, nodal areas >4, increased LDH and beta(2)-microglobulin, and high-risk IPI and FLIPI were associated with HT. In multivariate analysis, grade 3 histology and FLIPI retained prognostic significance. Only FLIPI predicted HT in grade 1-2 patients. 28 patients received salvage treatment for HT, with a CR rate of 52%. Median survival from transformation was 1.2 years, with 6/13 CR patients being alive >5 years after HT. CONCLUSION: FLIPI and histology were the most important variables predicting HT. Upon HT, only patients achieving CR reached prolonged survival, thus emphasizing the need for effective therapies once this event occurs.

Adult↗

PubMed2006

A functional variant in the CD209 promoter is associated with DQ2-negative celiac disease in the Spanish population.

AIM: To address the role of CD209 in celiac disease (CD) patients. Non-human leukocyte antigen (HLA) genetic factors in CD predisposition are poorly understood, and environmental factors like infectious pathogens may play a role. CD209 is a dendritic and macrophage surface molecule involved in pathogen recognition and immune activation. Recently, a functional variant in the promoter of the CD209 gene (-336A/G) has been shown to affect the transcriptional CD209 activity in vitro and it has been associated with a higher susceptibility to/or severity of infection. METHODS: The study population was composed of two case-control cohorts of 103 and 386 CD patients and 312 y 419 healthy controls as well as a panel of 257 celiac families. Genotyping for the -336A/G CD209 promoter polymorphism was performed using a TaqMan 5' allelic discrimination assay. HLA-DQ was determined by hybridization with allele specific probes. RESULTS: Initially, the case-control and familial studies did not find any association of the -336 A/G CD209 genetic variant with CD susceptibility. However, the stratification by HLA-DQ2 did reveal a significant association of CD209 promoter polymorphism in the HLA-DQ2 (-) group (carrier A vs GG in DQ2 (-) vs DQ2 (+) patients (P = 0.026, OR = 3.71). CONCLUSION: The -336G CD209 allele seems to be involved in CD susceptibility in HLA-DQ2 (-) patients. Our results might suggest a possible role of pathogens in the onset of a minor group of CD patients.

Alleles↗

PubMed2006

mRNA expression of MAGE-A3 gene in leukemia cells.

Leukemia-associated antigens such as proteins encoded by MAGE genes might provide tools for immunotherapy of leukemia. Positive and negative results of MAGE-A gene expression in hematological malignancies have been reported. This led us to study MAGE-A gene expression in human leukemias using RT-PCR. Among 115 leukemias from various subtypes, 14/34 (41.17%) AML were positive for one of the three genes analyzed (MAGE-A1 1/32; MAGE-A3 10/32; MAGE-B2 3/12). Expression was also detected in 23/76 (30.26%) B-cell ALL patients (MAGE-A1 2/53; MAGE-A3 20/53; MAGE-B2 1/32). One of these patients expressed both MAGE-A1 (weak signal) and -A3 (strong signal) genes. Other patient with CML were positive for MAGE-B2 (1/5, 20%). MAGE-A3 expression data were corroborated by real time RT-PCR through determination of MAGE-A3 transcript levels. We concluded that the MAGE-A3 gene is expressed at the mRNA level in a proportion of human leukemias.

Adult↗

PubMed2006

High-dose radiation employing external beam radiotherapy and high-dose rate brachytherapy with and without neoadjuvant androgen deprivation for prostate cancer patients with intermediate- and high-risk features.

The role of neoadjuvant androgen deprivation (NAD) in high-risk prostate cancer patients receiving high-dose radiotherapy (RT) remains unstudied. To evaluate the effect of a course of NAD, we reviewed the experiences of three institutions treating these patients with combined RT and high-dose rate brachytherapy (HDR). Of 1260 prostate cancer patients with high-risk features (pretreatment prostate-specific antigen (PSA) > or =10, Gleason Score (GS) > or =7, or T stage > or =T2b), 560 received no NAD (n=308) or NAD for < or =6 months (n=252). Median dose to the prostate from RT and HDR was 42 and 23 Gy, respectively. Average total biologic equivalent prostate dose was >100 Gy (alpha/beta=1.2). Median follow-up was 4.3 years. Pretreatment characteristics were similar on chi(2) tables for all 560 patients treated with or without NAD including pretreatment PSA (P=0.11), GS (P=0.4), and clinical T stage (P=0.2). Outcomes worsened for patients receiving NAD (5-year distant metastasis (DM) 10 vs 5% (P=0.04); cause-specific survival (CSS), 93 vs 98% (P=0.005)). Higher 5-year DM rates and lower CSS occurred in NAD patients with a GS between 8 and 10 (n=112 (P=0.03, P=0.02)), pretreatment PSA> or =15 (n=136 (P=0.03, P=0.008)), and palpable disease > or =T2a (n=434 (P=0.04, P=0.02)). The only two significant risk factors for DM on Cox multivariate analysis were GS (P=0.003, HR 2.8) and NAD (P=0.03, HR 2.7). AD given before definitive high-dose RT did not benefit prostate cancer patients with intermediate- and high-risk features. We favor the use of concurrent/adjuvant AD over prolonged NAD for prostate cancer patients for whom AD is clinically indicated.

Aged↗

PubMed2006

Comparison of clinical, ultrasonographic, and biochemical differences at the beginning of puberty in healthy girls born either small for gestational age or appropriate for gestational age: preliminary results.

CONTEXT: There are limited and controversial data concerning puberty characteristics in girls born small for gestational age (SGA). OBJECTIVE: The objective of the study was to document clinical, ultrasonographic, and biochemical characteristics at the beginning of puberty in matched healthy girls born either SGA or appropriate for gestational age (AGA) recruited from the community. PATIENTS: Inclusion criteria were breast Tanner stage II and a body mass index between the 10th and 95th percentiles. INTERVENTIONS: Recruited subjects underwent a complete physical exam, bone age, and ultrasound measurements of the internal genitalia. Hormonal assessment included fasting early morning dehydroepiandrosterone sulfate, androstenedione, SHBG, inhibin-B, FSH, LH, estradiol (E2), 17-hydroxyprogesterone (17OH Prog), and testosterone. Thereafter, a GnRH agonist test (leuprolide 500 microg, sc) was performed with FSH and LH at time 3 and 24 h for E2, 17OH Prog, and testosterone. RESULTS: Sixty-five girls (35 AGA, 30 SGA) with a mean age of 9.9 +/- 1.03 (7.8-12.5) yr, similar bone age/chronological age (1.02 +/- 0.8 in AGA and 1 +/- 0.76 in SGA), median height of 1.35 +/- 0.06 cm, and similar waist to hip ratio were included. No differences in the presence of pubic hair, axillary hair, apocrine odor, or ultrasound measurements were found. SGA girls had increased baseline E2 as well as stimulated E2 and 17OH Prog. CONCLUSIONS: In a preliminary sample of lean, healthy girls recruited from the community born either SGA or AGA, we observed slight hormonal differences at the beginning of puberty. Longitudinal follow-up of this cohort will allow us to understand whether these differences are maintained and have a clinical impact in their pubertal development.

17-alpha-Hydroxyprogesterone↗

PubMed2006

Ephrin-A5 modulates the topographic mapping and connectivity of commissural axons in murine hippocampus.

Entorhinal and commissural/associational projections show a non-overlapping distribution in the hippocampus proper and the dentate gyrus. The expression of Ephrins and their Eph receptors in the developing hippocampus indicates that this family of axonal guidance molecules may modulate the formation of these connections. Here we focused on the role of the ephrin-A5 ligand in the development of the main hippocampal afferents. In situ hybridization showed that ephrin-A5 mRNA was detected mainly in the principal cells of the hippocampus proper and in the dentate gyrus throughout postnatal development. Immunocytochemical analyses revealed prominent expression of the EphA3 receptor, a putative receptor for ephrin-A5, in the main cells and the neuropil of the developing hippocampus. Tracing experiments in ephrin-A5(-/-) mice showed that commissural projections were transiently altered in the hippocampus proper at P5, but they were mistargeted throughout the postnatal development in the dentate gyrus. Immunocytochemistry with anti-calbindin antibodies revealed that the dentate mossy fiber projection was not altered in ephrin-A5(-/-) mice. Electron microscopy studies showed alterations in the density of synapses and spines in commissural/associational layers, but not in entorhinal layers, and in the mossy fibers in these animals. Taken together, these findings indicate that ephrin-A5 signaling is involved in the formation and maturation of synapses in the hippocampus.

Animals↗

PubMed2006

Distribution and expression pattern of the nitrergic system in the cerebellum of the sheep.

The nitrergic system produces nitric oxide as an atypical neurotransmitter in the nervous system. Nitric oxide is produced from l-arginine through specific enzymes known as nitric oxide synthases. Of these, the more abundant form in neurons is the constitutive neuronal nitric oxide synthase, although the inducible isoform can be expressed as well, especially following stress or other injuries. The excessive formation of nitric oxide results in protein nitration, particularly at tyrosine residues, thus the presence of nitrotyrosine can be used as a marker of nitric oxide production. In previous studies we have shown the distribution of the components of the nitrergic system in the cerebellum of rodents, where neuronal nitric oxide synthase immunoreactivity was present in stellate and basket cells, and occasionally in granule cells. Here, we present evidence that in the sheep, as a model of larger mammals, most cerebellar neurons display an intense immunostaining for neuronal nitric oxide synthase, including unipolar brush cells, and Lugaro and Golgi neurons, which are not immunoreactive in rodents. In addition, weak immunoreactivity for inducible nitric oxide synthase and nitrotyrosine was found in particular cell types, indicating a basal expression for these markers. Our results suggest a larger dependence on the nitrergic system for the cerebella of larger mammals. Since this increase happens in both activating and inhibitory neurons of the cerebellar circuitry, we propose that in these animals there is a higher steady-state regulation of the cerebellum based on nitric oxide.

Animals↗

PubMed2006

Epistatic interaction between FCRL3 and NFkappaB1 genes in Spanish patients with rheumatoid arthritis.

BACKGROUND: A Japanese study has described a strong association between rheumatoid arthritis and several polymorphisms located in the Fc receptor-like 3 (FCRL3) gene, a member of a family of genes related to Fc receptors located on chromosome 1q21-23. OBJECTIVES: To evaluate the association between rheumatoid arthritis and FCLR3 polymorphisms in a large cohort of Caucasian patients with rheumatoid arthritis and healthy controls of Spanish origin. Owing to the described functional link between the FCRL3 polymorphisms and the transcription factor nuclear factor kappaB (NFkappaB), a functional polymorphism located in the NFkappaB1 gene was included. METHODS: 734 patients with rheumatoid arthritis from Madrid and Granada, Spain, were included in the study, along with 736 healthy controls. Polymorphisms in the FCRL3 gene were studied by TaqMan technology. The -94ins/delATTG NFkappaB1 promoter polymorphism was analysed by fragment analysis after polymerase chain reaction with labelled primers. Genotypes were compared using 3x2 contingency tables and chi2 values. RESULTS: No overall differences were found in any of the FCRL3 polymorphisms and in the NFkappaB1 promoter polymorphism when patients were compared with controls. However, when stratified according to NFkappaB1 genotypes, a susceptibility effect of FCRL3 polymorphisms was observed in patients who were heterozygotes for NFkappaB1 (pc = 0.003). CONCLUSIONS: The FCRL3 polymorphisms associated with rheumatoid arthritis in a Japanese population are not associated per se with rheumatoid arthritis in a Spanish population. A genetic interaction was found between NFkappaB1 and FCRL3 in Spanish patients with rheumatoid arthritis. These findings may provide a general rationale for divergent genetic association results in different populations.

Adult↗

PubMed2006

An IFNG polymorphism is associated with interferon-beta response in Spanish MS patients.

Interferon-beta is a biological treatment widely used in multiple sclerosis (MS). However, not every patient responds equally well to this therapy. In this study, our aim was to evaluate the influence of a dinucleotide microsatellite located in the first intron of the interferon-gamma gene on relapse eradication in a group of interferon-beta-treated patients. Our results show a very different allelic distribution when patients with relapses were compared with relapse-free patients.

Dinucleotide Repeats↗

PubMed2006

Prenatal RR fluctuations dynamics: detecting fetal short-range fractal correlations.

OBJECTIVE: Several studies have suggested that the analysis of heart rate variability (HRV) during gestation provides indications of the development or maturation of fetal cardiovascular regulatory mechanisms. In this study, we evaluate the existence of short-range fractal-like correlations in fetal RR fluctuations data from the second half of human gestation. METHODS: Fifty-six short-term abdominal ECG recordings were obtained from low-middle-risk pregnant women. Gestational age varied from estimated 21 weeks to term. For comparison, RR-interval data of 51 healthy adults were also analysed. RESULTS: Principal findings along the gestational period explored were the existence of fractal RR dynamics in prenatal fetal data as revealed by the short-range scaling exponent alpha(1). No significant differences of alpha(1) (p = 0.4770) were found between fetal (median 1.2879) and adult data (median 1.3214), either between the fetal cases before or after 24 weeks (p = 0.6116) despite observing more variation at early stages. However, fetal RR data did involve lower magnitude in comparison with adults as we found significant differences in pNN20 and SDNN values. CONCLUSION: The fetal short-range fractal behaviour of RR data could then be linked to the functional development of the parasympathetic activity, which appears to become manifested before 21 weeks of gestation.

Adolescent↗

PubMed2006

Morbidity and mortality in liver retransplantation.

INTRODUCTION: The incidence of orthotopic liver retransplantation (re-OLT) ranges from 6% to 11%. The most frequent causes of early re-OLT are allograft failure, uncontrolled acute rejection, and vascular complications. MATERIALS AND METHODS: A retrospective study of 512 orthotopic liver transplants (OLTs) in 482 patients over 15 years. RESULTS: The incidence of re-OLT was 6.6%, with a higher percentage of men requiring re-OLT than first-time OLT (75.0% vs 63.0%, P < .05). The reasons for re-OLT were thrombosis 21.7%, aneurysm 6.5%, stenosis 3.2%, primary nonfunction (PNF) 21.7%, and chronic rejection or recurrence of the initial disease 40.4%. Complications included PNF (22.0%), acute renal failure (65.6%), postoperative infection (87.5%), and adult respiratory distress syndrome (9.4%; P < .05). No differences were seen in the incidence of septicemia or postoperative hemorrhage. The average survival was much lower in re-OLT (21.8 days) compared with OLT (194.5 days; P < .05). The mortality rates in re-OLT were 100% for primary biliary cirrhosis, 85.7% for HCV, 50% for alcoholic cirrhosis, and 20% for HBV. A direct association between the Model for End-stage Liver Disease (MELD) score and the number of complications was present. DISCUSSION: There was a greater requirement for re-OLT in men and those patients transplanted due to hepatitis B virus cirrhosis and fulminant hepatitis (P < .05). The re-OLT patients had no greater incidence of sepsis compared with the OLT patients, although they did have a greater incidence of primary graft dysfunction, acute renal failure, adult respiratory distress syndrome, and postoperative infection (P < .05). The MELD was a good parameter for predicting graft evolution. Re-OLT in patients with primary biliary cirrhosis and hepatitis C virus was associated with a high degree of mortality.

Humans↗

PubMed2006

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay to quantify Parietaria judaica major allergens, Par j 1 and Par j 2.

BACKGROUND: Parietaria pollen is one of the most important causes of pollinosis in Mediterranean countries. Parietaria judaica pollen extract presents two major allergens, Par j 1 and Par j 2, that belong to the lipid transfer protein family. OBJECTIVE: To develop an ELISA for quantification of both major allergens of P. judaica pollen extracts, and to assert correlation of these allergens content with the allergenic activity of extracts. METHODS: Natural Par j 1-Par j 2 allergens were purified by gel filtration, ion exchange, and affinity chromatography and identified by mass spectrometry. Rabbit antisera were obtained using this protein preparation as antigen and used for immunoaffinity purification of nPar j 1-Par j 2. BALB/c mice were immunized with the immunopurified nPar j 1-Par j 2 and after fusion and screening by direct ELISA, 5D4 monoclonal antibody was selected as capture antibody to develop a quantitative two-site ELISA. Bound proteins were detected by a biotinylated Par j 1-Par j 2-specific polyclonal antibody. RESULTS: The optimized ELISA was developed from 25 to 8000 pg/mL of purified Par j 1-Par j 2, and a linear portion of 200-1000 pg/mL. The intraassay and interassay coefficients of variation were lower than 7% and 14% respectively. The assay was very sensitive and specific as it had a detection limit of 25 pg/mL and did not detect reactivity with the same family plants, as Urtica. Par j 1-Par j 2 allergens content was measured in 14 P. judaica and two P. officinalis pollen extracts showing a significant correlation with their allergenic activity measured by enzyme allergosorbent test inhibition. CONCLUSIONS: The results proved the usefulness of the two-sandwich ELISA for the standardization of Parietaria pollen extracts intended for clinical use, because of its good correlation with allergenic potency.

Allergens↗

PubMed2006

Purified allergens vs. complete extract in the diagnosis of plane tree pollen allergy.

BACKGROUND: Plane tree pollen allergy is a clinical disorder affecting human population in cities of Europe, North America, South Africa, and Australia. OBJECTIVE: To compare IgE-reactivity of the natural and recombinant forms of two major plane allergens, Pla a 1 and Pla a 2, with the reactivity of Platanus acerifolia pollen extract. METHODS: Forty-seven patients with P. acerifolia allergy, 15 of them monosensitized, and 24 control subjects were included in the study. Natural Pla a 1 and Pla a 2 were purified by standard chromatographic methods and recombinant proteins were expressed in Escherichia coli. Skin prick test and determination of specific IgE were performed with commercial P. acerifolia extract and natural and recombinant purified allergens. RESULTS: Pla a 1 and Pla a 2 were responsible for 79% of the IgE-binding capacity against P. acerifolia pollen extract. A high correlation has been found between the IgE response to nPla a 1 (R = 0.80; P < 0.001) or nPla a 2 (R = 0.79; P < 0.001) vs. P. acerifolia extract as well as between natural and recombinant Pla a 1 (R = 0.89; P < 0.001). Skin testing showed no significant differences between extract and nPla a 2, whereas a higher reactivity was found with nPla a 1. In contrast, rPla a 1 revealed markedly reduced sensitivity in comparison with extract by skin prick test and specific IgE. The sensitivity of the mix Pla a 1+Pla a 2 was 100% and 87.5% for monosensitized and polysensitized patients, respectively, with no false-positive reactions detected. Conclusion Pla a 1 and Pla 2 are sufficient for a reliable diagnosis of P. acerifolia in most patients and induce comparable skin test reactivity as a whole extract.

Adolescent↗