51 research outputs found

    Flux-cutting and flux-transport effects in type-II superconductor slabs in a parallel rotating magnetic field

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    The magnetic response of irreversible type-II superconductor slabs subjected to in-plane rotating magnetic field is investigated by applying the circular, elliptic, extended-elliptic, and rectangular flux-line-cutting critical-state models. Specifically, the models have been applied to explain experiments on a PbBi rotating disk in a fixed magnetic field Ha{\bm H}_a, parallel to the flat surfaces. Here, we have exploited the equivalency of the experimental situation with that of a fixed disk under the action of a parallel magnetic field, rotating in the opposite sense. The effect of both the magnitude HaH_a of the applied magnetic field and its angle of rotation αs\alpha_s upon the magnetization of the superconductor sample is analyzed. When HaH_a is smaller than the penetration field HPH_P, the magnetization components, parallel and perpendicular to Ha{\bm H_a}, oscillate with increasing the rotation angle. On the other hand, if the magnitude of the applied field, HaH_a, is larger than HPH_P, both magnetization components become constant functions of αs\alpha_s at large rotation angles. The evolution of the magnetic induction profiles inside the superconductor is also studied.Comment: 12 pages, 29 figure

    Guidelines for the use of human immunoglobulin therapy in patients with primary immunodeficiencies in Latin America

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    Antibodies are an essential component of the adaptative immune response and hold long-term memory of the immunological experiences throughout life. Antibody defects represent approximately half of the well-known primary immunodeficiencies requiring immunoglobulin replacement therapy. In this article, the authors review the current indications and therapeutic protocols in the Latin American environment. Immunoglobulin replacement therapy has been a safe procedure that induces dramatic positive changes in the clinical outcome of patients who carry antibody defects.Fil: Condino Neto, A.. Universidade de Sao Paulo; BrasilFil: Costa Carvalho, B. T.. Universidade Federal de Sao Paulo; BrasilFil: Grumach, A. S.. No especifíca;Fil: King, A.. No especifíca;Fil: Bezrodnik, Liliana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Área de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oleastro, M.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Leiva, L.. Louisiana Tech University; Estados UnidosFil: Porras, O.. Hospital Nacional de Ninos ˜ Dr Carlos Sáenz Herrera"; Costa RicaFil: Espinosa Rosales, F. J.. Instituto Nacional de Pediatría; MéxicoFil: Franco, J. L.. Universidad de Antioquia; ColombiaFil: Sorensen, R. U.. Universidad de La Frontera; Chil

    The Interplay between Entamoeba and Enteropathogenic Bacteria Modulates Epithelial Cell Damage

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    In amoebiasis, a human disease that is a serious health problem in many developing countries, efforts have been made to identify responsible factors for the tissue damage inflicted by the parasite Entamoeba histolytica. This amoeba lives in the lumen of the colon without causing damage to the intestinal mucosa, but under unknown circumstances becomes invasive, destroying the intestinal tissue. Bacteria in the intestinal flora have been proposed as inducers of higher amoebic virulence, but the causes or mechanisms responsible for the induction are still undetermined. Mixed intestinal infections with Entamoeba histolytica and enteropathogenic bacteria, showing exacerbated manifestations of disease, are common in endemic countries. We implemented an experimental system to study amoebic virulence in the presence of pathogenic bacteria and its consequences on epithelial cells. Results showed that amoebae that ingested enteropathogenic bacteria became more virulent, causing more damage to epithelial cells. Bacteria induced release of inflammatory proteins by the epithelial cells that attracted amoebae, facilitating amoebic contact to the epithelial cells and higher damage. Our results, although a first approach to this complex problem, provide insights into amoebic infections, as interplay with other pathogens apparently influences the intestinal environment, the behavior of cells involved and the manifestations of the disease

    Patients with primary immunodeficiencies are a reservoir of poliovirus and a risk to polio eradication

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    ABSTARCT: Immunodeficiency-associated vaccine-derived polioviruses (iVDPVs) have been isolated from primary immunodeficiency (PID) patients exposed to oral poliovirus vaccine (OPV). Patients may excrete poliovirus strains for months or years; the excreted viruses are frequently highly divergent from the parental OPV and have been shown to be as neurovirulent as wild virus. Thus, these patients represent a potential reservoir for transmission of neurovirulent polioviruses in the post-eradication era. In support of WHO recommendations to better estimate the prevalence of poliovirus excreters among PIDs and characterize genetic evolution of these strains, 635 patients including 570 with primary antibody deficiencies and 65 combined immunodeficiencies were studied from 13 OPV-using countries. Two stool samples were collected over 4 days, tested for enterovirus, and the poliovirus positive samples were sequenced. Thirteen patients (2%) excreted polioviruses, most for less than 2 months following identification of infection. Five (0.8%) were classified as iVDPVs (only in combined immunodeficiencies and mostly poliovirus serotype 2). Non-polio enteroviruses were detected in 30 patients (4.7%). Patients with combined immunodeficiencies had increased risk of delayed poliovirus clearance compared to primary antibody deficiencies. Usually, iVDPV was detected in subjects with combined immunodeficiencies in a short period of time after OPV exposure, most for less than 6 months. Surveillance for poliovirus excretion among PID patients should be reinforced until polio eradication is certified and the use of OPV is stopped. Survival rates among PID patients are improving in lower and middle income countries, and iVDPV excreters are identified more frequently. Antivirals or enhanced immunotherapies presently in development represent the only potential means to manage the treatment of prolonged excreters and the risk they present to the polio endgame. Keywords: Poliovirus eradication, Immunodeficiency-associated vaccine-derived polioviruses, Oral poliovirus vaccine, Humoral immunodeficiency, Combined immunodeficiency, Primary immunodeficienc

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Association of diamine oxidase and histamine N-methyltransferase polymorphisms with presence of migraine in a group of Mexican mothers of children with allergies

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    Background: Low histamine metabolism has been suggested to play a role in the pathogenesis of allergy and migraine. We investigated the possible association between 2 single-nucleotide polymorphisms (SNP), C314T HNMT and C2029G DAO, and the presence and severity of migraine and migraine-related disability. Materials and methods: We studied the frequency of C314T HNMT and C2029G DAO allelic variants in 162 mothers of children with allergies (80 with migraine and 82 without) using a TaqMan-based qPCR Assay and a case–control model. We conducted a logistic regression analysis to examine the association between migraine and the allelic and haplotype variants. Results: Mutant C2029G DAO SNP was found significantly more frequently in the group of women with migraine than in controls (OR, 1.6; 95% CI, 1.1–2.1). No significant differences were found in frequencies of genotypes or alleles in the case of C314T HNMT SNP. Both mutated alleles were associated with migraine-related disability. Coexistence of alleles for both SNPs (haplotypes) showed a strong association with migraine. Haplotypes containing both mutated alleles (either heterozygous or homozygous) were very strongly associated with MIDAS grade IV migraine (OR, 45.0; 95% CI, 5.2–358). This suggests that mutant alleles of C314T for histamine N-methyltransferase (HNMT) and C2029G for diamine oxidase (DAO) polymorphisms may interact in a way that increases the risk and impact of migraine. Conclusions: We suggest a synergistic association between HNMT and DAO functional polymorphisms and migraine; this hypothesis must be further confirmed by larger studies. However, the characteristics and ethnic differences between analysed populations should be considered when interpreting the results. Resumen: Introducción: Se ha sugerido que una degradación disminuida de histamina puede contribuir en la patogénesis de migraña y alergia. Este trabajo investiga una posible asociación entre 2 polimorfismos de un solo nucleótido (SNP) de 2 enzimas que degradan histamina, C314T para la histamina N-metil-transferasa (HNMT) y C2029G para diaminoxidasa (DAO), con la presencia, discapacidad y severidad de la migraña. Material y métodos: Se reclutó a 162 madres de niños alérgicos (80 con migraña y 82 sin migraña) determinando las variantes alélicas por PRC tiempo real usando un modelo de casos y controles. Mediante regresión logística se determinaron las OR para los genotipos y haplotipos. Resultados: El alelo mutado G para DAO fue significativamente más frecuente en el grupo de mujeres migrañosas que en los controles (OR = 1,6; IC del 95% = 1,1-2,1). No encontramos diferencias significativas para el alelo mutado T de la HNMT. Ambos alelos mutados estuvieron asociados a la discapacidad causada por la migraña. La coexistencia de ambas mutaciones (haplotipos) mostró una fuerte asociación con migraña. Los haplotipos que tenían ambos alelos mutados (ya sea como homocigotos o heterocigotos) estuvieron fuertemente asociados a la discapacidad por migraña grado iv (OR = 45,0, IC del 95% = 5,2-358). Esto sugiere que los alelos mutados T para HNMT y G para DAO pueden interactuar incrementando el riesgo y el impacto de la migraña. Conclusiones: Se sugiere una asociación sinérgica de polimorfismos de HNMT y DAO con migraña el cual debe ser confirmado en futuros estudios. La interpretación debe tomar en cuenta las características étnicas de la población estudiada. Keywords: Migraine, Histamine, Diamine oxidase, Polymorphism, Histamine N-methyltransferase, ABP1, Palabras clave: Migraña, Histamina, Polimorfismos, Histamina N-metiltransferasa, Diaminoxidasa, ABP

    Asociación de polimorfismos de diaminoxidasa e histamina N metiltransferasa con la presencia, discapacidad y severidad de migraña en un grupo de madres mexicanas de niños alérgicos

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    Resumen: Introducción: Se ha sugerido que una degradación disminuida de histamina puede contribuir en la patogénesis de migraña y alergia. Este trabajo investiga una posible asociación entre 2 polimorfismos de un solo nucleótido (SNP) de 2 enzimas que degradan histamina, C314 T para la histamina N-metil-transferasa (HNMT) y C2029G para diaminoxidasa (DAO), con la presencia, discapacidad y severidad de la migraña. Material y métodos: Se reclutó a 162 madres de niños alérgicos (80 con migraña y 82 sin migraña) determinando las variantes alélicas por PRC tiempo real usando un modelo de casos y controles. Mediante regresión logística se determinaron las OR para los genotipos y haplotipos. Resultados: El alelo mutado G para DAO fue significativamente más frecuente en el grupo de mujeres migrañosas que en los controles (OR = 1,6; IC del 95% = 1,1-2,1). No encontramos diferencias significativas para el alelo mutado T de la HNMT. Ambos alelos mutados estuvieron asociados a la discapacidad causada por la migraña. La coexistencia de ambas mutaciones (haplotipos) mostró una fuerte asociación con migraña. Los haplotipos que tenían ambos alelos mutados (ya sea como homocigotos o heterocigotos) estuvieron fuertemente asociados a la discapacidad por migraña grado iv (OR = 45,0, IC del 95% = 5,2-358). Esto sugiere que los alelos mutados T para HNMT y G para DAO pueden interactuar incrementando el riesgo y el impacto de la migraña. Conclusiones: Se sugiere una asociación sinérgica de polimorfismos de HNMT y DAO con migraña el cual debe ser confirmado en futuros estudios. La interpretación debe tomar en cuenta las características étnicas de la población estudiada. Abstract: Background: Low histamine metabolism has been suggested to play a role in the pathogenesis of allergy and migraine. We investigated the possible association between 2 single-nucleotide polymorphisms (SNP), C314 T HNMT and C2029G DAO, and the presence and severity of migraine and migraine-related disability. Materials and methods: We studied the frequency of C314 T HNMT and C2029G DAO allelic variants in 162 mothers of children with allergies (80 with migraine and 82 without) using a TaqMan-based qPCR Assay and a case-control model. We conducted a logistic regression analysis to examine the association between migraine and the allelic and haplotype variants. Results: Mutant C2029G DAO SNP was found significantly more frequently in the group of women with migraine than in controls (OR, 1.6; 95% CI, 1.1–2.1). No significant differences were found in frequencies of genotypes or alleles in the case of C314 T HNMT SNP. Both mutated alleles were associated with migraine-related disability. Coexistence of alleles for both SNPs (haplotypes) showed a strong association with migraine. Haplotypes containing both mutated alleles (either heterozygous or homozygous) were very strongly associated with MIDAS grade iv migraine (OR, 45.0; 95% CI, 5.2-358). This suggests that mutant alleles of C314 T for HNMT and C2029G for DAO polymorphisms may interact in a way that increases the risk and impact of migraine. Conclusions: We suggest a synergistic association between HNMT and DAO functional polymorphisms and migraine; this hypothesis must be further confirmed by larger studies. However, the characteristics and ethnic differences between analysed populations should be considered when interpreting the results Palabras clave: Migraña, Histamina, Polimorfismos, Histamina N-metiltransferasa, Diaminoxidasa, ABP1, Keywords: Migraine, Histamine, Diamine oxidase, Polymorphism, Histamine N-methyltransferase, ABP

    Guidelines for the use of human immunoglobulin therapy in patients with primary immunodeficiencies in Latin America

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    Antibodies are an essential component of the adaptative immune response and hold long-term memory of the immunological experiences throughout life. Antibody defects represent approximately half of the well-known primary immunodeficiencies requiring immunoglobulin replacement therapy. in this article, the authors review the current indications and therapeutic protocols in the Latin American environment. Immunoglobulin replacement therapy has been a safe procedure that induces dramatic positive changes in the clinical outcome of patients who carry antibody defects. (C) 2012 SEICAP Published by Elsevier Espana, S.L. All rights reserved.Univ São Paulo, Inst Biomed Sci, Dept Immunol, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Dept Pediat, São Paulo, BrazilFac Med ABC, Dept Med, São Paulo, BrazilHosp Ninos Luis Calvo Mackenna, Santiago, ChileHosp Ninos Dr Ricardo Gutierrez, Immunol Grp, Buenos Aires, DF, ArgentinaHosp Juan P Garrahan, Div Immunol, Buenos Aires, DF, ArgentinaLouisiana State Univ, Hlth Sci Ctr, Dept Pediat, New Orleans, LA USAHosp Nacl Ninos Dr Carlos Saenz Herrera, San Jose, Costa RicaInst Nacl Pediat, Unidad Invest Inmunodeficiencias, Mexico City, DF, MexicoUniv Antioquia, Primary Immunodeficiencies Grp, Medellin, ColombiaUniv La Frontera, Fac Med, Temuco, ChileUniversidade Federal de São Paulo, Sch Med, Dept Pediat, São Paulo, BrazilWeb of Scienc
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