Infection of mice by the enteroaggregative E. coli strain 042 and two mutant derivatives overexpressing virulence factors: impact on disease markers, gut microbiota and concentration of SCFAs in feces.

Several pathogenic Escherichia coli strains cause diarrhea. Enteroaggregative E. coli (EAEC) strains are one of the diarrheagenic pathotypes. EAEC cells form a "stacked-brick" arrangement over the intestinal epithelial cells. EAEC isolates express, among other virulence determinants, the AggR transcriptional activator and the aggregative adherence fimbriae (AAF). Overexpression of the aggR gene results in increased expression of virulence factors such as the aff genes, as well as several genes involved in specific metabolic pathways such as fatty acid degradation (fad) and arginine degradation (ast). To support the hypothesis that induction of the expression of some of these pathways may play a role in EAEC virulence, in this study we used a murine infection model to evaluate the impact of the expression of these pathways on infection parameters. Mice infected with a mutant derivative of the EAEC strain 042, characterized by overexpression of the aggR gene, showed increased disease symptoms compared to those exhibited by mice infected with the wild type (wt) strain 042. Several of these symptoms were not increased when the infecting mutant, which overexpressed aggR, lacked the fad and ast pathways. Therefore, our results support the hypothesis that different metabolic pathways contribute to EAEC virulence.

Pharmacologic control of homeostatic and antigen-driven proliferation to target HIV-1 persistence.

The presence of latent human immunodeficiency virus 1 (HIV-1) in quiescent memory CD4 + T cells represents a major barrier to viral eradication. Proliferation of memory CD4 + T cells is the primary mechanism that leads to persistence of the latent reservoir, despite effective antiretroviral therapy (ART). Memory CD4 + T cells are long-lived and can proliferate through two mechanisms: homeostatic proliferation via γc-cytokine stimulation or antigen-driven proliferation. Therefore, therapeutic modalities that perturb homeostatic and antigen-driven proliferation, combined with ART, represent promising strategies to reduce the latent reservoir. In this study, we investigated a library of FDA-approved oncology drugs to determine their ability to inhibit homeostatic and/or antigen-driven proliferation. We confirmed potential hits by evaluating their effects on proliferation in memory CD4 + T cells from people living with HIV-1 on ART (PLWH) and interrogated downstream signaling of γc-cytokine stimulation. We found that dasatinib and ponatinib, tyrosine kinase inhibitors, and trametinib, a MEK inhibitor, reduced both homeostatic and antigen-driven proliferationby >65%, with a reduction in viability <45%, ex vivo. In memory CD4 + T cells from PLWH, only dasatinib restricted both homeostatic and antigen-driven proliferation and prevented spontaneous rebound, consistent with promoting a smaller reservoir size. We show that dasatinib restricts IL-7 induced proliferation through STAT5 phosphorylation inhibition. Our results establish that the anti-cancer agent dasatinib is an exciting candidate to be used as an anti-proliferative drug in a clinical trial, since it efficiently blocks proliferation and iswell tolerated in patients with chronic myeloid leukemia (CML).

Dietary supplementation with spray-dried porcine plasma has prebiotic effects on gut microbiota in mice.

In animal models of inflammation and in farm animals, dietary inclusion of spray-dried porcine plasma (SDP) reduces mucosal inflammation. Here, we study whether these effects could be mediated by changes in the intestinal microbiota and if these changes are similar to those induced by oral antibiotics. Weaned 21-day-old C57BL/6 mice were divided into 3 groups: the CTL group, fed the control diet; the COL group, administered low doses of neomycin and colistin; and the SDP group, supplemented with 8% SDP. After 14 days, analysis of the fecal microbiome showed that the microbiota profiles induced by SDP and the antibiotics were very different, thus, SDP has prebiotic rather than antibiotic effects. At the phylum level, SDP stimulated the presence of Firmicutes, considerably increasing the lactobacilli population. It also enhanced the growth of species involved in regulatory T-lymphocyte homeostasis and restoration of the mucosal barrier, as well as species negatively correlated with expression of pro-inflammatory cytokines. At the mucosal level, expression of toll-like receptors Tlr2, Tlr4 and Tlr9, and mucous-related genes Muc2 and Tff3 with regulatory and barrier stability functions, were increased. SDP also increased expression of Il-10 and Tgf-ß, as well as markers of macrophages and dendritic cells eventually promoting an immune-tolerant environment.

[Paraneoplastic opsoclonus myoclonus ataxia syndrome]. / Síndrome opsoclono-mioclono-atáxico paraneoplásico.

Opsoclonus myoclonus ataxia syndrome (OMAS) is a very infrequent paraneoplastic or postinfectious movement disorder, which may occur at any age, most commonly between 6 and 36 months of age. In four days, a previously healthy 30-month-old girl progressively developed gait instability, intention tremor, dysarthric speech, irritability and altered sleep. Physical and neurological examination did not reveal additional deficits. She had had a transient exanthema without fever three weeks before. Basic blood analysis, serologies, cultures, urine toxin detection, EEG and cerebral CT were normal. Lumbar puncture showed minimal lymphocytosis. On the fifth day following the onset of symptoms, the ataxia worsened, precluding sitting, and the tremor was aggravated by intentional myoclonus. Chaotic saccadic, large amplitude multidirectional but conjugated eye movements appeared. An opsoclonus was suspected and a chest X-ray and CT revealed a paravertebral thoracic mass. Surgery confirmed a localized ganglioneuroblastoma. Blood neuron-specific enolase and urine catecholamine levels were normal. Opsoclonus disappeared with high doses of prednisone and following surgery. Ataxia improved but the patient still required low daily doses of steroids for one year.

Variation in the levels of inflammatory cytokines depending on ischemic time: effects on respiratory variables.

OBJECTIVES: We sought to evaluate the association between ischemic times, cytokines-interleukin (IL)-6, IL-1b, tumor necrosis factor-alpha, sIL-2r, IL-8, and IL-10-and alterations in gaseous exchange. MATERIALS AND METHODS: This prospective study of 42 orthotopic liver transplantation (OLT) recipients examined ischemic times and respiratory variables measured as alterations in intrapulmonary shunt and in the Po(2)/Fio(2) ratio. Centrifuged blood samples were frozen at -80 degrees C for storage. The Inmulite-One system (Euro/Dpc, Gwynedd, UK) was used to determine the concentration of cytokines. For statistical analysis, we used the Pearson correlation coefficient. RESULTS: The average cold ischemic time was 478 minutes (range, 35-929) and warm ischemic time was 69.58 minutes (range, 20-180). The warm ischemic time affected the degree of shunt at the end of the operation (P < .027) and the levels of IL-10 (P < .018) and IL-6 (P < .000). The final degree of shunting and IL-10 (P < .044) showed a correlation. The cold ischemic time affected IL-1 (P < .046) and IL-8 levels (P < .023). The reperfusion syndrome was correlated with the final levels of IL-10 (P < .064) and of IL-8 (P < .066). CONCLUSION: Warm and cold ischemic times affect the final cytokine levels and the degree of intrapulmonary shunt.

Best blood sample draw site during liver transplantation.

BACKGROUND: The present study sought to identify whether there were higher inflammatory cytokine levels in blood samples drawn from the pulmonary artery, radial artery, portal vein, or reperfused graft during each transplantation phase to determine the best site. METHODS: We examined 39 consecutive patients undergoing liver transplantation for their blood cytokine levels at various sites. Comparison of levels permitted us to select the best blood sample draw site, considering the best site to be the one showing the highest cytokine levels. RESULTS: During hepatectomy and neohepatic phases, the best site was the radial artery; during the anhepatic phase, the portal vein; and during reperfusion, the reperfused graft. CONCLUSIONS: The radial artery constituted, an optimal sample draw site, considering the best one to show the highest cytokine levels.

Polymorphisms of interleukin-6 and tumor necrosis factor gene promoters and cardiorespiratory function following liver transplantation: a preliminary study.

INTRODUCTION: The interindividual variability in cardiorespiratory function during liver transplantation (OLT) has been attributed to various factors, including polymorphisms in immunity genes known to affect the circulation levels of cytokines. AIM: To evaluate polymorphisms of genes encoding for interleukin-6 (IL6) and tumor necrosis factor (TNF) in association with cardiorespiratory function in OLT. DESIGN: Prospective observational study. PATIENTS AND METHODS: We studied 62 consecutive patients who had OLT performed in our hospital between 2004 and 2005. Polymorphisms at positions -308 and -409 of TNF gene, as well as those at -174 and -574 of IL6 gene were determined in all patients by means of PCR-RFLPs. Associations were carried out using chi-square tests and analysis of variance. A bilateral P < .05 was accepted as significant. RESULTS: No statistically significant associations were observed. CONCLUSIONS: A relationship between the polymorphisms studied and respiratory function in OLT was lacking. These results must be interpreted with caution due to the limited sample size.

Síndrome opsoclono-mioclono-atáxico paraneoplásico / Paraneoplastic opsoclonus myoclonus ataxia syndrome

El síndrome opsoclono-mioclono-atáxico (SOMA)es un trastorno del movimiento muy infrecuente, de origenautoinmune y de aparición a cualquier edad, másprobable entre los 6-36 meses.Se presenta el caso de una niña de 30 meses, previamentesana, que desarrolló progresivamente en cuatrodías marcha inestable, temblor intencional, habla escandida,irritabilidad y trastorno del sueño. El resto de laexploración física y neurológica era normal. Presentóexantema leve tres semanas antes. Al ingreso, la analíticageneral, cultivos, tóxicos en orina, serologías, electroencefalogramay tomografía cerebral (TC) fueron normales.La punción lumbar mostró linforraquia leve. Al quintodía desde el inicio, la ataxia impedía la sedestación y eltemblor era generalizado agravado probablemente pormioclonias intencionales. Aparecieron entonces movimientosoculares rápidos, sacádicos, multidireccionales,aunque conjugados. Ante el diagnóstico de opsoclono,se solicitó radiografía de tórax observando una masa torácicaparavertebral, corroborada en la TC torácica. Lacirugía confirmó un ganglioneuroblastoma localizado. Laenolasa neuronal específica en sangre y catecolaminasen orina fueron normales. El opsoclono desapareció conprednisona oral a altas dosis y tras cirugía. Un año despuésprecisaba dosis mínima de corticoide por apariciónde leve inestabilidad de la marcha e irritabilidad al suspenderla medicación(AU)

Opsoclonus myoclonus ataxia syndrome (OMAS)is a very infrequent paraneoplastic or postinfectiousmovement disorder, which may occur at any age, mostcommonly between 6 and 36 months of age.In four days, a previously healthy 30-month-oldgirl progressively developed gait instability, intentiontremor, dysarthric speech, irritability and altered sleep.Physical and neurological examination did not revealadditional deficits. She had had a transient exanthemawithout fever three weeks before. Basic blood analysis,serologies, cultures, urine toxin detection, EEG and cerebralCT were normal. Lumbar puncture showed minimallymphocytosis. On the fifth day following the onsetof symptoms, the ataxia worsened, precluding sitting,and the tremor was aggravated by intentional myoclonus.Chaotic saccadic, large amplitude multidirectionalbut conjugated eye movements appeared. An opsoclonuswas suspected and a chest X-ray and CT revealeda paravertebral thoracic mass. Surgery confirmed alocalized ganglioneuroblastoma. Blood neuron-specificenolase and urine catecholamine levels were normal.Opsoclonus disappeared with high doses of prednisoneand following surgery. Ataxia improved but the patientstill required low daily doses of steroids for one year(AU)

Dietary plasma proteins, the intestinal immune system, and the barrier functions of the intestinal mucosa.

The intestinal mucosa contributes to homeostasis by preventing the entrance of biological and chemical agents across the epithelium that could alter the stability of the system. This protective function is especially important at the time of weaning, when animals are exposed to infectious agents and to numerous stresses such as the change of environment and diet. Diets supplemented with spray-dried plasma or plasma protein fractions have been shown to improve growth performance of farm animals and have been proposed as an alternative to antibiotics. In this review, we summarize our findings on the mechanism of action of dietary plasma proteins using a rat model of intestinal inflammation, based on the administration of Staphylococcus aureus enterotoxin B (SEB). Staphylococcal enterotoxin B activates the gut-associated lymphoid tissue (GALT), increasing T-lymphocytes in Peyer's patches and the number of activated T lymphocytes in mesenteric lymph nodes (organized GALT). In the lamina propria SEB increased cytotoxic T gammadelta and natural killer cell populations of the diffuse GALT. Staphyloccocal enterotoxin B significantly increased proinflammatory cytokines in Peyer's patches and mucosa. Plasma protein supplements modulated the mucosal immune response in organized and diffuse GALT, protecting GALT from possible excessive activation by the SEB challenge. These effects are accompanied by a reduction of proinflammatory cytokine production, supporting the view that changes in cytokine production mediate the effects of dietary plasma proteins during intestinal inflammation. The increase in mucosal permeability and intestinal secretion induced by SEB was associated with decreased expression of mucosal tight-junction and adherent-junction proteins. Both plasma and plasma protein fractions prevented the effects of SEB on intestinal permeability, thus reducing the exposure of the host to microbial and food antigens across the interstitial space. These findings indicate that dietary plasma proteins modulate functional and structural properties of the intestinal mucosa.

RECOMENDACIONES DE BUENA PRÁCTICA CLÍNICA: Gastropatía por antiinflamatorios no esteroideos / RECOMMENDATIONS FOR GOOD CLINICAL PRACTICE: NSAID gastropathy

La gastropatía por antiinflamatorios no esteroideos (AINE)es una patología frecuente que debemos tener en cuentaante todo paciente que nos consulte por problemas de dispepsiao astenia de larga evolución. Actualmente se cifran en16.500 las muertes anuales por complicaciones por el consumode estos fármacos y en más de cien mil, los ingresoshospitalarios anuales, datos que pueden darnos una idea dela verdadera importancia del problema. Los factores de riesgoimplicados más frecuentemente y que siempre debemostener en cuenta son la edad (mayor de 65 años), la toma conjuntade más de un AINE, la toma de anticoagulantes o corticoides,ISRS o ISRNS, ulcus o gastropatía previos y la existenciade alguna enfermedad concomitante grave. Otroaspecto a tener en cuenta es la erradicación del Helicobacter(H.) pylori, lo que parece que es coste efectivo y reduce elriesgo de complicaciones gastrointestinales (GI). Ante un pacientecon factores de riesgo en el que vayamos a iniciar untratamiento con AINE o ya lo siguiera por cualquier causa,que tuviera un evento GI, debemos, siempre que se pueda,suspender el AINE y testar el H. pylori para erradicarlo sisale positivo y posteriormente reiniciar el tratamiento conAINE más conveniente (si se puede, siempre el menos gastrolesivo)teniendo en cuenta los factores de riesgo GI y cardiovascularesy asociando un protector gástrico. El papel actualde los COX-2, como AINE y con un riesgo de lesión GImenor que los AINE clásicos, debe tenerse también en cuenta,si bien debe barajarse el riesgo cardiovascular del pacienteen la decisión de dicha alternativa terapéutica (AU)

NSAIDs gastropathy is a frequent disease that we shouldtake into account whenever there is a patient who consultsdue to long term dyspepsia or asthenia. Currently there areabout 16,500 deaths a years due to complicatons from consumptionof these drugs and there are more than one hundredthousand hospitalizations per year. This could give usan idea of the true importance of the problem. The most frequentlyinvolved risk factors and those which should also betaken into account are age (older than 65 years), combineduse of an NSAID, anticoagulants or corticosteroids, SSRI orSNRIS, ulcer or previous gastropathy and the existence ofany serious concomitant disease. Another aspect to consideris the eradication of Helicobacter (H.) pylori, where it seemsthat it is cost effective and reduces gastrointestinal complications.When a patient has risk factors and we are going toinitiate NSAID treatment or continue it for any reason, or ifwhen the patient is taking it for any reason, he or she has aGI event, we should always, when possible, suspend theNSAID and test for H. Pylori to see if it is positive and to eradicateit and then reinitiate the best possible NSAID treatment(if possible, always with the least gastrointestinalharm) considering the GI and cardiovascular risk factors andassociating a gastrointestinal protector. The current role ofCOX-2, as NSAID and with a risk of less GI injury than theclassical NSAIDs should also be taken into account althoughthe cardiovascular risk of the patient should be consideredin the decision of the therapeutic alternative (AU)

Generation of rabbit antibodies against death ligands by cDNA immunization.

Specificity problems, especially in immunoblot analysis, have been shown for several commercial antibodies raised against the death ligand Fas ligand (FasL) using conventional protein and/or peptide immunizations. In this work, we have optimized the development of rabbit antisera and isolated pAb against the death ligands FasL, Apo2 ligand/TRAIL and Apo3 ligand/TWEAK by cDNA intramuscular immunization. This alternative approach has generated specific pAb in all three cases, which are useful for immunoblot purposes. The present data suggest that for the production of antibodies against certain glycosylated membrane proteins, cDNA immunization could be the method of choice.

Hen egg white fractionation by ion-exchange chromatography.

Major hen egg white proteins have been widely studied for their functional properties but these studies still are unable to explain, alone, all of the biological properties of hen egg white. Hence, it is still interesting to produce pure and non-altered proteins to improve our knowledge on the biological properties of hen egg white. Presently, identification and characterization of both bioactive peptides and minor proteins from hen egg white is essential work for progressing in the understanding of hen egg white biological properties. With this objective in mind, a new process for a complete "mucin free" hen egg white fractionation based on ion exchange chromatography is proposed. "Mucin free" egg white is fractionated into six different fractions. Four of them are high-recovery yield purified fractions of lysozyme, ovotransferrin, ovalbumin and flavoprotein. The two other fractions are enriched in recently detected minor proteins in hen egg white.

Aldosterone reduces crypt colon permeability during low-sodium adaptation.

Fluid and electrolyte absorption by colonic crypts depends on the transport properties of crypt cellular and paracellular routes and of the pericryptal sheath. As a low-Na(+) diet increases aldosterone and angiotensin II secretion, either hormone could affect absorption. Control and adrenalectomized (ADX) Sprague-Dawley rats were kept at a high-NaCl (HS) diet and then switched to low-NaCl (LS) diet for 3 days. Aldosterone or angiotensin II plasma concentrations were maintained using implanted osmotic mini-pumps. The extracellular Na(+) concentration in isolated rat distal colonic mucosa was determined by confocal microscopy using a low-affinity Na(+) -sensitive fluorescent dye (Sodium red, and Na(+) -insensitive BODIPY) bound to polystyrene beads. Crypt permeability to FITC-labelled dextran (10 kDa) was monitored by its rate of escape from the crypt lumen into the pericryptal space. Mucosal ion permeability was estimated by transepithelial electrical resistance (TER) and amiloride-sensitive short-circuit current (SCC). The epithelial Na(+) channel, ENaC, was determined by immunolocalization. LS diet decreased crypt wall permeability to dextran by 10-fold and doubled TER. Following ADX, aldosterone decreased crypt wall dextran permeability, increased TER, increased Na(+) accumulation in the pericryptal sheath and ENaC expression even in HS. Infusion of angiotensin II to ADX rats did not reverse the effects of aldosterone deprivation. These findings indicate that aldosterone alone is responsible for both the increase in Na(+) absorption and the decreased paracellular and pericryptal sheath permeability.

Pericryptal myofibroblast growth in rat descending colon induced by low-sodium diets is mediated by aldosterone and not by angiotensin II.

Pericryptal myofibroblast growth in descending colonic crypts correlates with the activation of the renin-angiotensin-aldosterone system. Earlier work showed that during the transition from a high-Na(+) (HS) to low-Na(+) (LS) diet there are changes in the colonic crypt wall and pericryptal sheath. As LS diet increases both aldosterone and angiotensin II, the aim here was to determine their individual contributions to the trophic changes in colonic crypts. Experiments were conducted on control and adrenalectomized Sprague-Dawley rats fed an HS diet and then switched to LS diet for 3 days and supplemented with aldosterone or angiotensin II. The actions of the angiotensin-converting enzyme inhibitor captopril, the angiotensin receptor antagonist losartan and the aldosterone antagonist spironolactone on extracellular matrix proteins, claudin 4 and E-cadherin myofibroblast proteins, alpha-smooth muscle actin (alpha-SMA) and OB-cadherin (cadherin 11), angiotensin type 1 and TGFbetar1 membrane receptors were determined by immunolocalization in fixed distal colonic mucosa. The LS diet or aldosterone supplementation following ADX in HS or LS increased extracellular matrix, membrane receptors and myofibroblast proteins, but angiotensin alone had no trophic effect on alpha-SMA. These results show that aldosterone stimulates myofibroblast growth in the distal colon independently of dietary Na(+) intake and of angiotensin levels. This stimulus could be a genomic response or secondary to stretch of the pericryptal sheath myofibroblasts accompanying enhanced rates of crypt fluid absorption.

Valor de screening del antígeno específico prostático en el cáncer de próstata / Value of prostatic specific antigen screening in the cancer of prostate

No disponible