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Biomedical subjects

A Muñoz

Publications and source records attributed to A Muñoz.

At least 37 records · Page 2Linked to original sources
PubMed2005

Long-term outcome of allogeneic or autologous haemopoietic cell transplantation for acute lymphoblastic leukaemia in second remission in children. GETMON experience 1983-1998.

We present a retrospective study of long-term outcome and predictive factors of survival and relapse in 219 paediatric patients with acute lymphoblastic leukaemia (ALL) in second remission. They received allogeneic (allo) or autologous (auto) haemopoietic cell transplantation (HCT) depending on the availability of a matched sibling donor. The probability of event-free survival (EFS) for the total patient group was 0.35+0.03 at 14 years. No significant differences were observed for EFS between allo- and auto-HCT: 0.39+0.05 vs 0.32+0.04 (P=0.43). A better EFS was seen in patients with a late relapse (LR) (P=0.06 and 0.02, for allogeneic and autologous respectively). Significantly better EFS was observed in allo-HCT patients under 10 years of age and in auto-HCT patients with leukocytes at diagnosis below 25 x 109/l and late relapse. Predictive factors of failure in both groups were early relapse (ER), medullary relapse and age over 10 years. The probability of relapse (RP) for the total group of patients was 0.57+0.03, and it was significantly higher in auto-HCT patients: 0.65+0.04 vs 0.42+0.06 (P=0.002). Factors predictive for relapse were medullary and early relapse, auto-HCT and WBC >25 x 109/l at diagnosis.

Child↗
PubMed2005

Novel MASP2 variants detected among North African and Sub-Saharan individuals.

The lectin pathway of the complement system is activated when mannan-binding lectin (MBL) in complex with MBL-associated serine protease 2 (MASP-2) binds to carbohydrate structures on microorganisms. Structural gene mutations and promoter polymorphisms in the MBL2 gene responsible for low-MBL serum levels are present in all human populations and associate with increased risk of infection. Recently, investigations on Danes revealed the existence of a mutation on the MASP2 gene, which introduces an amino acid substitution in the CUB1 domain (Asp105Gly; numbering refers to the mature protein), and is associated with reduction in the level of MASP-2 in serum. Here, we present the results of a sequence-based typing analysis of the MBL2 and MASP2 gene polymorphisms in a group of 65 Africans (50 North Africans and 15 Sub-Saharan) and of 104 Spaniards. The analysis identified three novel exon 3 MASP2 variants introducing amino acid substitutions at positions 84 (Arg-->Gln), 103 (Arg-->Cys) and 111 (Pro-->Leu) in the CUB1 domain. None of these variants were identified in Spaniards. The Arg84Gln was detected in four of the 15 Sub-Saharans. The Arg103Cys and Pro111Leu variants were detected only among North Africans (two and four individuals, respectively). The Asp105Gly variant was similarly represented among Spaniards and North Africans (three and two individuals, respectively), which appears to be a lower frequency than that reported for Danes (5.5%). As reported for MBL2, the marked geographic distribution of the new MASP2 variants may represent an evolutionary adaptation to different environments.

Africa South of the Sahara↗
PubMed2005

Double-blind, placebo-controlled study of immunotherapy with Parietaria judaica: clinical efficacy and tolerance.

Allergy to Parietaria causes significant morbidity in most Mediterranean areas. The aim of this study is to investigate the efficacy and tolerance of Parietaria depot extract at 25 BU/mL (1.5 microg/mL Par j 1). We performed a multicenter double-blind, placebo-controlled study in rhinitic patients with/without asthma, sensitized to Parietaria. 42 patients followed 20-month immunotherapy. Clinical efficacy was based on symptom and medication scores and the percentage of healthy days (days without symptoms or medication). Severity of asthma/rhinitis scales, visual analogue scale, evaluation of the treatment by doctors and patients, immediate and delayed cutaneous response and quality of life questionnaires were also studied. The active group showed a sustained decrease in symptoms (p = 0.008), medication (p = 0.009) and both (p = 0.001), and an increase in healthy days (p = 0.001) throughout the study, with a threefold increase of healthy days and almost a three time reduction in medication only after one year of treatment. Asthma and rhinitis severity scales also decreased after immunotherapy, and blinded clinical evaluation by physicians confirmed efficacy in 85% and 77% of the active patients. Patient's self-evaluation returned similar results. None of these changes were observed with placebo. Immediate cutaneous response was significantly reduced at the maintenance phase in the active group and remained reduced throughout the study. Late-phase response after intradermal testing also showed a statistical decrease in actively treated patients. Immunotherapy was well tolerated and every systemic reaction reported was mild. In conclusion, immunotherapy with Parietaria 25 BU/mL is an effective and safe treatment for patients with respiratory allergies.

Adolescent↗
PubMed2004

Crystal and magnetic structure of the double perovskite Sr2CoUO6: a neutron diffraction study.

Sr2CoUO6 double perovskite has been prepared as a polycrystalline powder by solid-state reaction, in air. This material has been studied by X-ray, neutron powder diffraction (NPD) and magnetic measurements. At room temperature, the crystal structure is monoclinic, space group P2(1)/n, Z= 2, with a= 5.7916(2), b= 5.8034(2), c= 8.1790(3) A, beta= 90.1455(6)degrees. The perovskite lattice consists of a completely ordered array of CoO6 and UO6 octahedra, which exhibit an average tilting angle phi= 11.4 degrees. Magnetic and neutron diffraction measurements indicate an antiferromagnetic ordering below TN = 10 K. The low-temperature magnetic structure was determined by NPD, selected among the possible magnetic solutions compatible with the P2(1)/n space group, according with the group theory representation. The propagation vector is k= 0. A canted antiferromagnetic structure is observed below TN = 10 K, which remains stable down to 3 K, with an ordered magnetic moment of 2.44(7)mu(B) for Co2+ cations. The magnetic moment calculated from the Curie-Weiss law at high temperatures (5.22 mu(B)/f.u.) indicates that the orbital contribution is unquenched at high temperatures, which is consistent with high-spin Co2+((4)T(1g) ground state) in a quasi-regular octahedral environment. Magnetic and structural features are consistent with an electronic configuration Co2+[3d(7)]-U6+[Rn].

Journal Article↗
PubMed2004

Entomological aspects of Chagas' disease transmission in the domestic habitat, Argentina.

OBJECTIVE: To study the risk of Trypanosoma cruzi domestic transmission using an entomological index and to explore its relationship with household's characteristics and cultural aspects. METHODS: There were studied 158 households in an endemic area in Argentina. Each household was classified according to an entomological risk indicator (number of risky bites/human). A questionnaire was administered to evaluate risk factors among householders. RESULTS: Infested households showed a wide range of risk values (0 to 5 risky bites/human) with skewed distribution, a high frequency of lower values and few very high risk households. Of all collected Triatoma infestans, 44% had had human blood meals whereas 27% had had dogs or chickens blood meals. Having dogs and birds sharing room with humans increased the risk values. Tidy clean households had contributed significantly to lower risk values as a result of low vector density. The infested households showed a 24.3% correlation between time after insecticide application and the number of vectors. But there was no correlation between the time after insecticide application and T. infestans' infectivity. The statistical analysis showed a high correlation between current values of the entomological risk indicator and Trypanosoma cruzi seroprevalence in children. CONCLUSIONS: The risk of T. cruzi domestic transmission assessed using an entomological index show a correlation with children seroprevalence for Chagas' disease and householders' habits.

Animals↗
PubMed2004

Evolution of biological effects of Aznalcóllar mining spill in the Algerian mouse (Mus spretus) using biochemical biomarkers.

The status of Guadiamar stream, polluted in 1998 by metals spilled from a pyrite tailings dam, was monitored from 1999 to 2001 to assess possible biological effects in terrestrial ecosystems of Doñana National Park (DNP) (Andalusia, SW Spain). The Algerian mouse (Mus spretus) was used as bioindicator at different Guadiamar and Doñana sites. Eleven biochemical parameters, including the activities of antioxidative and biotransforming enzymes and oxidative damages to biomolecules, were assayed in liver as biomarkers responsive to metals and organic pollutants. In 2001, metals were also determined in kidney and their possible correlation with biomarker responses was studied. Contents of Pb, Cd and As significantly correlated with several antioxidative enzymes. Biomarkers responsive to oxidative stress indicate the presence of transition metals in the high and medium Guadiamar course, and their response diminished with the distance to the collapsed dam. The high ethoxyresorufin-O-deethylase (EROD) activity of mice from the medium and low Guadiamar course point to organic pollutants, such as the pesticides used in intensive crops grown in areas nearby Doñana. The increasing responses of several biomarkers at reference sites may suggest a progressive pollution of key Doñana ecosystems.

Animals↗
PubMed2004

Fraction of cases of acquired immunodeficiency syndrome prevented by the interactions of identified restriction gene variants.

Previous research has demonstrated isolated effects of host genetic factors on the progression of human immunodeficiency virus type 1 (HIV-1) infection. In this paper, the authors present a novel use of multivariable methods for estimating the prevented fraction of acquired immunodeficiency syndrome (AIDS) cases attributable to six restriction genes after accounting for their epidemiologic interactions. The methods presented will never yield a prevented fraction above 1. The study population consisted of a well-characterized cohort of 525 US men with HIV-1 seroconversion documented during follow-up (1984-1996). On the basis of a regression tree approach using a Cox proportional hazards model for times to clinical AIDS, the combinations of genes associated with the greatest protection, relative to the lack of a protective genotype, consisted of: 1) C-C chemokine receptor 5 (CCR5)-Delta 32 and C-C chemokine receptor 2 (CCR2)-64I (relative hazard = 0.44); 2) interleukin 10 (IL10)-+/+ in combination with CCR5-Delta 32 or CCR2-64I (relative hazard = 0.45); and 3) IL10-+/+ in combination with stromal-derived factor (SDF1)-3 'A and CCR5 promoter P1/approximately P1 (relative hazard = 0.37). Overall, 30% of potential AIDS cases were prevented by the observed combinations of restriction genes (95% confidence interval: 7, 47). However, the combined effect was confined to the first 4 years following HIV-1 seroconversion. Additional research is needed to identify AIDS restriction genes with stronger and long-lasting protection to better characterize the genetic epidemiology of HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed2004

[Brainstem gliomas].

Brainstem gliomas have been increasingly understood in the last two decades and they are nowadays regarded as an heterogeneous group of tumors with tendency towards the pediatric age, where they account for 10-20% of brain neoplasms. Besides the well known diffuse tumor, several subtypes, with a different biological behaviour, amenable to surgical resection and better prognosis, have been identified, giving rise to many classifications and terms. In the other way, attention has been recently paid to adult brainstem gliomas in contrast to pediatric tumors. Based on a review of the literature, we describe the different subtypes of brainstem gliomas, with particular interest on therapeutic approaches and differences between pediatric and adult tumors, employing iconography from our series.

Adult↗
PubMed2004

Long-term results of high-dose chemotherapy and autologous stem cell rescue for high-risk neuroblastoma patients: a report of the Spanish working party for BMT in children (Getmon).

The authors retrospectively analyzed the long-term outcome of 67 patients over 1 year of age at diagnosis with high-risk neuroblastoma (stage 4 or stage 3 with N-myc amplification) who were treated with megatherapy and stem cell rescue from 1984 to 1998. Median age at transplant was 4 years (range 1.6-15 years). The source of cells was peripheral stem cells in 29 and bone marrow in 38 patients. In 12 patients, an in vitro purging of bone marrow harvest was performed. Most patients were conditioned with melphalan, BCNU, and VM-26. After transplant 19 patients received complementary treatment with IL-2 (16) or 13-cis-retinoic acid (3). Six patients (8%) died from transplant-related toxicity and 39 from disease progression. Three patients were alive with active disease at the time of analysis. Nineteen patients are alive and disease-free at a median follow-up of 104 months. Five-year event-free survival is 0.30. Survival of patients who received a purged graft was not significantly better than the rest. Post-transplant complementary treatment significantly improved overall and event-free survival (p = .01 and p = .04, respectively).

Adolescent↗
PubMed2003

Histopathology and reorganization of chandelier cells in the human epileptic sclerotic hippocampus.

Impairment of GABA-mediated inhibition is one of the main hypotheses invoked to explain seizure activity, both in experimental models and in human epilepsy. We have studied the distribution and the neurochemical characteristics of certain GABAergic circuits in the normal and epileptic human sclerotic hippocampal formation. We have focused our attention mainly on chandelier cells because, together with basket cells, they are considered to have powerful effects on spike generation. Chandelier cells represent a unique type of interneuron whose axon terminals (Ch-terminals) form synapses with the axon initial segments of cortical pyramidal cells and granular cells of the dentate gyrus. Different neurochemical subpopulations of chandelier cells have been identified by immunocytochemistry, mainly in the neocortex. Markers for Ch-terminals include the GABA transporter 1 (GAT-1), the polysialylated form of the cell-surface glycoprotein neural cell adhesion molecule (PSA-NCAM) and the calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB). In the normal hippocampal formation, GAT-1- and PV-immunoreactive (-ir) Ch-terminals were identified in the granular and polymorphic layers of the dentate gyrus, in the strata pyramidale and oriens of the CA fields, and in the pyramidal layer of the subicular complex. In addition, and in contrast to the hippocampus and dentate gyrus, subsets of Ch-terminals in the upper pyramidal layer of the normal subiculum express CB and PSA-NCAM. The sclerotic hippocampus of epileptic patients presented an impressive morphological and neurochemical reorganization of Ch-terminals and basket formations. This was apparent in the dentate gyrus and hippocampal formation, but not in the subiculum, which appeared to remain unaltered. Principally, numerous and more complex PV- and CB-ir Ch-terminals, as well as dense PV-ir basket formations, appeared in some hippocampal segments, whereas in other regions there was a lack of labelled elements. These changes varied considerably not only between different patients, but also within different hippocampal fields in a given patient. In general, the changes were not correlated with the clinical characteristics or degree of histopathological alterations observed in the patients, such as granular cell dispersion, neuron loss and proliferation of mossy fibres. However, some surviving neurons in the regions adjacent to the areas of neuron loss were consistently innervated by dense basket formations and complex Ch-terminals. These results indicate that, in the human epileptic hippocampus, GABAergic circuits are more highly modified than previously thought. When considered along with other extrahippocampal alterations, we suggest that these changes are important in the pathophysiology of temporal lobe epilepsy associated with hippocampal sclerosis.

Adolescent↗
PubMed2003

Interaction between the noradrenergic and serotonergic systems in locomotor hyperactivity and striatal expression of Fos induced by amphetamine in rats.

It is classically considered that Amphetamine acts by increasing extracellular dopamine levels. However, some data suggest a relevant role of other neurochemical systems. The striatum is of particular interest to the study of this question. We have investigated the involvement of the noradrenergic and serotonergic systems and their possible interaction in the striatal responses to Amphetamine using a double behavioral and immunohistochemical approach (i.e., changes in locomotor activity and striatal expression of Fos). In normal rats, Amphetamine induced locomotor hyperactivity and striatal expression of Fos. Pretreatment with the alpha1-adrenergic-receptor antagonist Prazosin or lesion of the serotonergic system significantly reduced the locomotor hyperactivity and striatal Fos expression induced by Amphetamine. Administration of Prazosin to rats with serotonergic denervation did not produce any further reduction in the Amphetamine-induced locomotor hyperactivity or striatal Fos expression compared with that observed in rats with serotonergic denervation only. Amphetamine did not induce a detectable increase in Fos expression in dopamine-denervated striata, and elicited intense rotation towards the dopamine-denervated side. This suggests that striatal dopamine release is essential in the Amphetamine-induced effects on striatal neurons. However, the noradrenergic system plays an important role, and the serotonergic system is necessary for mediating the effects of the Amphetamine-induced noradrenergic stimulation. Concurrent stimulation of dopaminergic and serotonergic receptors appears necessary to regulate Amphetamine-induced responses in the striatal neurons.

Adrenergic alpha-Antagonists↗
PubMed2003

NMR studies of phenylbenzohydroxamic acid and kinetics of complex formation with nickel(II).

The behavior of N-phenylbenzohydroxamic acid (PBHA) in organic solvents has been investigated by (1)H and (13)C NMR spectroscopy. Measurements in acetone at different temperatures and concentrations enable one to individualized two signals, in a 20/80 area ratio, which were ascribed to partition of PBHA between two isomers, HZ (cis) and HE (trans). The dependence of the low-intensity peak on concentration and temperature strongly suggests dimer formation. Since only the HZ form can give dimers, it may be concluded that in acetone PBHA is present mainly in the HE form. (13)C NMR measurements in methanol yielded a 50/50 [HZ]/[HE] ratio. The equilibria and kinetics of complex formation in aqueous solutions between Ni(II) and PBHA were investigated by spectrophotometric and stopped-flow techniques at 25 degrees C and 0.2 M ionic strength. Two reaction paths, involving the binding of Ni(2+) to the neutral PBHA and to its anion, were observed. The rate constants of the forward and reverse steps are k(1) = (7.1 +/- 0.3) x 10(2) M(-)(1) s(-)(1) and k(-1) = (4.9 +/- 0.6) s(-)(1) for the step involving the undissociated PBHA and k(2) = (5.5 +/- 0.7) x 10(4) M(-)(1) s(-)(1) and k(-2) = (1.2 +/- 0.1) s(-)(1) for the step involving the anion. The k(2) value indicates that the PBHA anion reacts with Ni(2+) according to Eigen's mechanism and that in water the cis form prevails. The k(1) value is lower by a factor of 13 compared to the value estimated on the basis of Eigen's mechanism, suggesting that at least 90% of the neutral ligand is present in a nonreactive conformation.

Journal Article↗
PubMed2003

Fronto-orbital remodeling without orbito-naso-frontal bandeau.

INTRODUCTION: Fronto-orbital bilateral advance is the procedure of choice for the treatment of craniosynostosis affecting most of the anterior area of the skull and orbitomalar regions. The aim of the technique is to achieve a supra-orbital bilateral bar and a frontal bone. We have introduced a modification in order to simplify the technique. PATIENTS AND METHODS: From November 1998 to January 2002, 18 patients with craniosynostosis have been surgically treated using our technique. The mean age when the treatment was performed was 6.93 months (range 3 to 22 months). Brain computed tomography (CT) scans and three-dimensional (3-D) reconstruction of CT scans were performed before and after treatment. SURGICAL TECHNIQUE: A bifrontal craniotomy was performed taking the osteotomy up to the supraorbital rim. A new frontal bone was obtained from another region of the cranium creating new orbital edges. The osteosynthesis was conducted using absorbable materials. RESULTS: The follow-up of the patients ranged from 3 months to 3 years. All patients were studied using CT scans and 3-D reconstruction of CT after treatment, which demonstrated the persistence of the fronto-orbital advance. No secondary complications related to the new technique were found in any of the patients. CONCLUSIONS: The frontal-orbital advance obtained was stable. The technique was simplified by not creating a supraorbital bar and by reducing the bone fixation points. The manipulation of both frontal lobes and orbital globes was negligible. The aesthetic results were excellent.

Bone Remodeling↗
PubMed2003

Immunopathology of an hDAF transgenic pig model liver xenotransplant into a primate.

BACKGROUND: hDAF transgenic pigs do not display the inherent hyperacute rejection reactions of pig-to-primate xenotransplants. The purpose of this study was to determine the immunopathologic phenomena following an hDAF transgenic pig hepatic orthotopic xenotransplant into a baboon. METHODS: Donor animals were unmodified pigs (n=4) and hDAF transgenic pigs (n=2). Recipient animals were baboons (Papio anubis). Liver biopsies were immunostained using monoclonal antibodies to C3, C5b-9, IgG, IgM, CD2, CD4, CD8, CD68, CD20, Bric 216, CD31, and fibrin, and polyclonal antibody to C4. RESULTS: hDAF transgenic grafts showed IgG, IgM, and C4 endothelial deposits. However, no fibrin, C3, or C5b9 deposits were observed after reperfusion. hDAF xenografts displayed CD31 staining in the portal spaces, perilobular areas, and at hepatic sinuisoidal levels. The baboon that lived for 4 days displayed either CD4 or CD8 T-cells periportal infiltrate. CONCLUSIONS: Future studies will seek to determine the physiologic role of CD31 hepatic sinusoidal expression in transgenic xenotransplants, and will also study the role of T-cell infiltrates in xenograft rejection.

Animals↗