Crisis asmática grave asociada con infección viral / Severe asthmatic crisis related to viral infection

Resumen ANTECEDENTES: 50% de las crisis asmáticas son desencadenadas por infecciones virales, su relación con parámetros clínicos no se ha descrito en los adultos. OBJETIVO: determinar la prevalencia de crisis asmáticas de acuerdo con el espectro viral y su asociación con características clínicas y mecánica respiratoria. MATERIAL Y MÉTODO: estudio clínico, prospectivo y observacional en el que se incluyeron pacientes con crisis asmática grave del 1 de diciembre de 2010 al 31 de diciembre de 2011. Se excluyeron los pacientes con sospecha de infección bacteriana. Se aplicó cuestionario de síntomas, se determinó panel viral por hisopado nasal, espirometría y estudios de laboratorio. Se obtuvo el consentimiento informado de los participantes. RESULTADOS: se incluyeron en el estudio 100 pacientes. La edad promedio fue de 39±14 años, IMC 27±4 kg/m2, escala de Borg 6.2±1.2, escala mMRC 2.6±0.6, tiempo de los síntomas 7±7 días, FEV1 de 42±14%, oximetría de pulso 88±3% y estancia de 4.5±1.7 días. El 47% de los pacientes tenía rinitis alérgica. Se aisló virus en 36% (rinovirus 15% y coronavirus 6%). Al comparar la causa viral vs no viral, se observó que los pacientes eran menores en el primer grupo (36±13 vs 43±17 años, p=0.014); no hubo diferencia entre grado de obstrucción y síntomas. A mayor severidad del asma hubo más aislamientos de virus. CONCLUSIÓN: las crisis asmáticas asociadas con virus respiratorios tienen comportamiento clínico similar al de las no asociadas. En los pacientes con menor edad y con comportamiento más grave se aíslan virus con más frecuencia.

Abstract BACKGROUND: 50% of asthma attacks are triggered by viral in fections; its relationship with clinical parameters has not been described in adults. OBJECTIVE: To determine the prevalence of asthma attacks according to viral spectrum and its association with clinical features and respiratory mechanics. MATERIAL AND METHOD: A clinical, prospective and observational study with patients with severe asthma attended from December 1st 2010 to December 31st 2011. We excluded patients with suspected bacterial infection. Symptom questionnaire was applied, it was determined by nasal swab viral panel, spirometry and laboratory studies. Informed consent was obtained. RESULTS: One hundred patients were included. Mean age was 39±14 years, BMI 27±4 kg/m2, Borg 6.2±1.2, mMRC 2.6±0.6, length of symptoms 7±7 days and FEV1 of 42±14%, pulse oximetry 88±3% and stay 4.5±1.7 days; 47% of patients had allergic rhinitis. Virus was isolated in 36% (15% rhinovirus and 6% coronavirus). Comparing the non-viral vs viral etiology, patients were younger (36±13 vs 43±17 years, p=0.014) there was no difference between the degree of obstruction and symptoms. A greater severity of asthma was related to more isolation. CONCLUSION: Asthma attacks associated with respiratory viruses have similar clinical behavior to not associated ones. In younger patients with more severe behavior virus are isolated more frequently.

O-Glycosylation in sprouting neurons in Alzheimer disease, indicating reactive plasticity.

Reactive plasticity, including axonal and dendritic sprouting and reactive synaptogenesis, has been proposed to contribute to the pathogenesis of several neurological disorders. This work was aimed at identifying the possible role of protein glycosylation in the brain from patients with Alzheimer disease (AD), using lectin histochemistry, as determinants of reactive plasticity. Results indicate an increase in the production of cryptic O-glycosidically linked proteins (NeuAcalpha2,6 Galbeta1,3GalNAcalpha1,0 Ser/Thr or sialyl-T-antigen) in neuritic sprouting in AD brains as determined by positive labeling with Amaranthus leucocarpus (ALL, T-antigen-specific) and Macrobrachium rosenbergii (MRL, specific for NeuAc5,9Ac2) lectins. Immunohistochemistry indicated that lectin staining was specific for the synaptic sprouting process (meganeurites) in AD. These results were confirmed using anti-synaptophysin and anti-GAP 43 antibodies, which recognized meganeurites and dystrophic neurites around amyloid-beta deposits. In normal control brains, labeling with the aforementioned lectins was restricted to microvessels. Control experiments with neuraminidase-treated brain samples revealed positivity to the lectin from Arachis hypogaea (PNA), which is specific for galactose. Our results suggest specific O-glycosylation patterns of proteins closely related to neuronal plasticity in AD.

Quantification of lectin in freshwater prawn (Macrobrachium rosenbergii ) hemolymph by ELISA.

An enzyme-linked immunoabsorbent assay was developed to quantify the lectin present in the hemolymph of the freshwater prawn Macrobrachium rosenbergii. This method involves the use of murine monoclonal IgG1 with kappa light chain (designated as 3G1) antibodies raised against the purified lectin, the assay that we developed recognized as little as 30 ng/ml of lectin, and was used to measure the lectin concentration in animals at different maturation stages. The highest concentration of lectin was identified in the hemolymph from post-larval prawns and the lowest in molt stage adult animals. The hemagglutination activity of the lectin was four-fold higher in adult than in juvenile specimens, although in all cases N-acetylated sugar residues, such as N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and N-acetyl-D-neuraminic acid were inhibitors of the lectin activity, suggesting that lectin plays a role in the transport of N-acetylated sugar in juvenile prawns. Our results indicate that lectin concentration and hemagglutinating activity could be influenced by developmental conditions of the freshwater prawn.

Chemical characterization of the lectin from the freshwater prawn Macrobrachium rosenbergii (De Man) by MALDI-TOF.

The serum of the freshwater prawn contains a sialic acid specific lectin (MrL) that agglutinates erythrocytes from rat and rabbit, as well as some Gram negative and positive bacterial strains. In this work, we performed the chemical characterization of the MrL purified by affinity chromatography on stroma from rat erythrocytes and by ion exchange chromatography. In its active form, MRL is a dimeric glycoprotein with 9.5 kDa per subunit. The amino acid sequence of the lectin was deduced from peptides obtained after trypsin treatment by matrix-assisted laser desorption ionization mass spectrometry-time of flight analysis (MALDI-TOF). The predicted amino acid sequence of the lectin showed 54% homology with the hyperglycemic hormone from Macrobrachium rosenbergii. It also showed homology with the variable region of the human immunoglobulin kappa (22%) and lambda (27%) light chains. The lectin is a glycoprotein with 11% (w/w) carbohydrate content and is constituted by Gal, Man, GlcNAc, GalNAc and NeuAc in a molar ratio of 4:3:2:1:0.6. The primary structure of the carbohydrate chains of the lectin from the freshwater prawn was determined by affinity chromatography of MrL-glycopeptides on Con A and LCA lectin columns, which indicated that the main carbohydrate chains conforming the lectin are N-glycosidically linked. Man3 GlcNAc2.1 oligosaccharides were the most abundant structures with 57%) followed by Gal1.3 Man3 GlcNAc2.8 with 24%. Our results suggest that the freshwater prawn possess a lectin in the hemolymph plasma, related to those from the immunoglobulin superfamily.

Identification of lectin isoforms in juvenile freshwater prawns Macrobrachium rosenbergii (DeMan, 1879).

From the serum of juvenile freshwater prawns, we isolated by affinity chromatography on glutaraldehyde-fixed rat erythrocytes stroma, immobilized in Sephadex G-25, a sialic acid specific lectin of 9.6 kDa per subunit. Comparative analysis against adult organisms purified lectin, by chromatofocusing, showed that the lectin from juvenile specimens is composed by four main isoforms with a pI of 4.2, 4.6, 5.1, and 5.6, whereas the lectin from adults is eluted at pH 4.2. The amino acid composition of the lectin obtained from adult and juvenile stages suggest identity, but the compositions are not identical since a higher content of carbohydrates was found in the lectin from younger organisms. The freshwater prawn lectin showed specificity toward N-acetylated amino sugar residues such as GlcNAc, GalNAc, Neu5Ac and Neu5,9Ac; but in juvenile organisms the lectin showed three times less hemagglutinating activity than the lectin from adults. Both lectins agglutinated rat, rabbit and chicken erythrocytes, indicating that Neu5,9Ac in specific O-glycosydically linked glycans seems to be relevant for the interaction of M. rosenbergii lectins with their specific cellular receptor. Our results suggest that the physicochemical characteristics of the lectin from the freshwater prawn are regulated through maturation.

The dynamics of mass migration.

We specify a set of equations defining a dynamic model of international migration and estimate its parameters by using data specially collected in Mexico. We then used it to project the a hypothetical Mexican community population forward in time. Beginning with a stable population of 10,000 people, we project ahead 50 years under three different assumptions: no international migration; constant probabilities of in- and out-migration, and dynamic schedules of out- and in-migration that change as migratory experience accumulates. This exercise represents an attempt to model the self-feeding character of international migration noted by prior observers and theorists. Our model quantifies the mechanisms of cumulative causation predicted by social capital theory and illustrates the shortcomings of standard projection methodologies. The failure to model dynamically changing migration schedules yields a 5% overstatement of the projected size of the Mexican population after 50 years, an 11% understatement of the total number of U.S. migrants, a 15% understatement of the prevalence of U.S. migratory experience in the Mexican population, and an 85% understatement of the size of the Mexican population living in the United States.

Purification and characterization of the hemagglutinin-neuraminidase of Porcine rubulavirus LPMV.

The Hemagglutinin-Neuraminidase (HN) from the LPMV strain of Porcine rubulavirus was purified from virions by ultracentrifugation in a continuous 20-60% sucrose gradient and by ion exchange chromatography. The HN is a glycoprotein of 66 kDa constituted by 50.5, 13.3 and 13.6% of non polar, uncharged polar, and charged polar amino acids, respectively. The HN contains 4% of carbohydrates, its glycannic portion is constituted by Man, Gal, GlcNAc, GalNAc, and Neu5Ac in 3:3:4:1:1 molar ratios. The HN possesses hemagglutinating activity in the presence of erythrocytes from several animal species, including human ABO, and treating the erythrocytes with neuraminidase or pronase abolishes this activity. The binding specificity of the purified HN was determined by hapten inhibition assays, indicating that the hemagglutinating activity of the HN is specific for sialic acid and Neu5Acalpha2,3Gal-containing structures.

[Specificity versus representativeness: methodological approaches to the study of Mexico-U.S. migration]. / Especificidad versus representatividad: enfoques metodologicos en el estudio de la migracion mexicana hacia Estados Unidos.

PIP: "This article compares two sources of data on Mexico-U.S. migration, based on radically different methodologies: the Mexican Migration Project (Promig) and the National Survey of Population Dynamics (Enadid).... This comparative study shows that a micro-social design drawing on multiple community samples, such as Promig, can solve the methodological conflict between specificity and representativeness.... The authors' research also highlights the problem of selectivity and specificity entailed by traditional surveys such as Enadid as a result of restricting their samples to international residents in Mexico and attempting to explain such a complex, socioeconomic process using a limited number of variables." (EXCERPT)^ieng

Immunity to porcine rubulavirus infection in adult swine.

The immune response against the porcine rubulavirus was analyzed in experimentally infected adult pigs. High titers of virus neutralizing and hemagglutinating inhibitory antibodies were identified in infected animals. The antibody specificity was directed towards HN, M, and NP rubula virion proteins; immunodominance of HN proteins was demonstrated. Peripheral blood mononuclear cells from infected, but not from non-infected pigs proliferated in vitro in response to virus antigenic stimuli, showing a bell-shaped plot with the highest peak at 5 weeks post-infection. Virus-induced lymphoblasts expressed CD4+ CD8+ phenotype, whereas lectin-induced lymphoblasts were mainly identified as CD4+ CD8- cells. Phenotype analysis of freshly prepared PBMC revealed increased number of both monocytes (PoM1+) and total T lymphocytes (CD2+) early during infection, with reduced values of B lymphocytes at 4 weeks post-infection. Decrease in CD4+ CD8- blood cells was observed at 3 weeks post-infection, whereas both CD4- CD8+ and CD4+ CD8+ cells increased 1 and 4 weeks post-infection, respectively. This work discusses the relevance of CD4+ CD8+ T cells in the control of porcine rubulavirus infection.

[The final result of the transition: the possible denial of the future of the elderly population and of the total population of Mexico]. / El curso final de la transicion: la negacion posible del futuro de la poblacion mayor y de la poblacion total en Mexico.

PIP: The author briefly considers some future implications of the demographic transition that Mexico has recently experienced. The author makes the following conclusions: that the transition was encouraged by national policies that were primarily economic in orientation; that significant social costs have had to be paid by the people in achieving the transition; that the migration patterns that were part of the transition have adversely affected rural areas; and that the significant aging of the population associated with the transition will cause major problems for society in the coming years.^ieng

NeuAc alpha 2,3gal-glycoconjugate expression determines cell susceptibility to the porcine rubulavirus LPMV.

Relevance of membrane sialoglycoconjugates as receptors for infection by the porcine rubulavirus has been determined in vitro by sugar and lectin competition assays and by inhibition of glycosylation. Our results show that NeuAc alpha 2,3Gal but not NeuAc alpha 2,6Gal inhibits the virus infectivity of Vero cells, and the virus was effectively blocked with the lectin Maackia amurensis, specific for NeuAc alpha 2,3Gal. Inhibition of the cellular glycosylation with tunicamycin, deoxinojirimycin as well as neuraminidase treatment diminishes the viral capacity to bind and infect this cell line. Dexamethasone, which promotes the activity of sialyl alpha 2,6 glycosyltransferase, also diminishes the cell susceptibility for infection. This is the first report confirming that NeuAc alpha-2,3Gal recognition is determinant in the pathogenesis of the porcine rubulavirus.

Purification of a N-acetyl-D-galactosamine specific lectin from the orchid Laelia autumnalis.

From the pseudobulbs of the orchid L. autumnalis a lectin was purified on immobilized porcine mucin with A + H blood group substance. This lectin is a dimeric glycoprotein of M(r) 12,000 with an Sw,20 of 2.2, showing haemagglutinating activity directed mainly to human A1 desialylated erythrocytes. The lectin possesses sugar specificity for N-acetyl-D-galactosamine and also shows high specificity for glycoproteins containing the T (galactose beta 1,3GA1NAc alpha 1,0 Ser/Thr) or the Tn antigen (GalNAc alpha 1,0 Ser/Thr).

Variability analysis of the T-cell receptors using three variability indexes.

In the absence of a three-dimensional structure for TCR molecules, several attempts to identify their hypervariable regions by variability methods have been made; this subjects is still troublesome. In this paper three different variability indexes were used: (i) the Kabat index, which is the classical measure of sequence variability, (ii) the modified Kabat index, successfully used in the beta-chain of T-cell receptors and (iii) an information-theoretical entropy concept, recently proposed as an improved measure of the variability. In order to identify the hypervariable regions in the TCR sequences, a Fourier filtering was applied on each variability profile. Results show that the three variability indexes have distinct resolutions for different levels of variability. Thus, the simultaneous use of these indexes compensates for the deficiency of any one of them in estimating variability. Applying the Fourier filtering, it is found that the hypervariable regions here identified, roughly coincide with the defined CDR-2 and CDR-3 in TCR by analogy with Ig. However, no hypervariable in the CDR-1 of alpha- and beta-chains was found. The study on the influence of sample size in variability analysis, indicates that results are independent of the sample size. Considering current structural models of TCR-peptide-MHC interaction, one can suggest that the low-variability characteristics of these regions is inherently related to the interaction with relatively conserved region on the alpha-helices of MHC.

Procedimientos de enfermería en evacuación aeromédica / Aeromedical evacuation

Se efectúa un análisis de las ventajas y problemas que se presentan durante la evacuación aeromédica de pacientes graves, especificando aquellos problemas fisiológicos y de organización que pueden determinar el éxito o el fracaso de una evacuación aeromédica. Se exponen las diferentes indicaciones y contraindicaciones en la evacuación aeromédica, así como igualmente se describen las características de la atención de enfermería y de los equipos que deben incluirse en una evacuación aeromédica