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1.
Environ Monit Assess ; 190(9): 564, 2018 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-30167796

RESUMEN

Tropical coastal lagoons are highly productive environments exhibiting high biodiversity. However, the use of these ecosystems by local communities is of concern, since this generally leads to environmental degradation. The Imboassica coastal lagoon, located in Macaé city, in Northern Rio de Janeiro, is an important ecosystem in the state, however, already displaying signs of anthropogenic impacts. Carnivorous fish Hoplias malabaricus specimens were sampled from this impacted site, as well as from a reference area. Fish from Imboassica Lagoon presented lower condition factor, lower cholinesterase activity, and higher percentage of erythrocyte micronuclei when compared to fish from the reference site. Metals in fish from Imboassica Lagoon were always higher than Encantada Lagoon, with some seasonal differences, where some metals were higher in the rainy season compared to the dry season in muscle tissue, with the exception of Cu, Fe, Sr, and Zn; and in the liver, except for Ba, Cd, Cr, Ni, and Sr. Cr and Mn in the edible muscle portion of the fish were higher than the limits established by Brazilian and International legislations as permissible for human consumption, thus leading to concerns regarding public health risks for the local population that use fish as their main protein source.


Asunto(s)
Ecosistema , Exposición a Riesgos Ambientales/efectos adversos , Peces/metabolismo , Metales Pesados/metabolismo , Alimentos Marinos/análisis , Agua de Mar , Contaminantes Químicos del Agua/metabolismo , Animales , Biomarcadores/metabolismo , Brasil , Colinesterasas/metabolismo , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente/métodos , Eritrocitos , Humanos , Hígado/metabolismo , Micronúcleos con Defecto Cromosómico , Músculos/metabolismo , Lluvia , Estaciones del Año , Clima Tropical
2.
J Environ Manage ; 203(Pt 2): 799-806, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27421699

RESUMEN

The biomass growth, pharmaceutical removal and light conversion efficiency of Chlorella sorokiniana under the presence of paracetamol (PC) and salicylic acid (SaC) were assessed and compared at two different concentrations of these pharmaceuticals (I: 25 mg l-1, II: 250 mg l-1). Microalgae were resistant to these concentrations and, moreover, their growth was significantly stimulated (p ≤ 0.05) under these drugs (biomass concentration increased above 33% PCI, 35% SaCI, 13% PCII and 45% SaCII, as compared with the respective positive controls). At the steady state of the semicontinuous culture, C. sorokiniana showed removal efficiencies above 41% and 69% for PCI and PCII, respectively; and above 93% and 98% for SaCI and SaCII, respectively. Under an irradiance of 370 µE m-2 s-1, higher quantum yields were reached by microalgae under the presence of drugs, either at dose I or II, than by the respective positive controls. These results point to C. sorokiniana as a robust strain for the bioremediation of paracetamol and salicylic acid concentrated wastewaters.


Asunto(s)
Acetaminofén , Microalgas , Ácido Salicílico , Purificación del Agua , Biomasa , Chlorella , Aguas Residuales , Contaminantes Químicos del Agua
3.
Neuroimage ; 135: 311-23, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-27138209

RESUMEN

We propose a novel method to harmonize diffusion MRI data acquired from multiple sites and scanners, which is imperative for joint analysis of the data to significantly increase sample size and statistical power of neuroimaging studies. Our method incorporates the following main novelties: i) we take into account the scanner-dependent spatial variability of the diffusion signal in different parts of the brain; ii) our method is independent of compartmental modeling of diffusion (e.g., tensor, and intra/extra cellular compartments) and the acquired signal itself is corrected for scanner related differences; and iii) inter-subject variability as measured by the coefficient of variation is maintained at each site. We represent the signal in a basis of spherical harmonics and compute several rotation invariant spherical harmonic features to estimate a region and tissue specific linear mapping between the signal from different sites (and scanners). We validate our method on diffusion data acquired from seven different sites (including two GE, three Philips, and two Siemens scanners) on a group of age-matched healthy subjects. Since the extracted rotation invariant spherical harmonic features depend on the accuracy of the brain parcellation provided by Freesurfer, we propose a feature based refinement of the original parcellation such that it better characterizes the anatomy and provides robust linear mappings to harmonize the dMRI data. We demonstrate the efficacy of our method by statistically comparing diffusion measures such as fractional anisotropy, mean diffusivity and generalized fractional anisotropy across multiple sites before and after data harmonization. We also show results using tract-based spatial statistics before and after harmonization for independent validation of the proposed methodology. Our experimental results demonstrate that, for nearly identical acquisition protocol across sites, scanner-specific differences can be accurately removed using the proposed method.


Asunto(s)
Algoritmos , Imagen de Difusión por Resonancia Magnética/instrumentación , Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador/instrumentación , Interpretación de Imagen Asistida por Computador/métodos , Técnica de Sustracción/instrumentación , Adulto , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Aumento de la Imagen/métodos , Almacenamiento y Recuperación de la Información/métodos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
4.
Clin Genet ; 87(2): e1-3, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25477152

RESUMEN

We have recently performed exome analysis in a 7 year boy who presented in infancy with an encephalopathy characterized by ataxia and myoclonic epilepsy. Parents were not consanguineous and there was no family history of the disease. Exome analysis did not show any pathogenic variants in genes known to be associated with seizures and/or ataxia in children, including all known human channelopathies. However, we have identified a mutation in KCNA2 that we believe to be responsible for the disease in our patient. This gene, which encodes a member of the potassium channel, voltage-gated, shaker-related subfamily, has not been previously described as a cause of disease in humans, but mutations of the orthologous gene in mice (Kcna2) are known to cause both ataxia and convulsions. The mutation is c.890C>A, leading to the amino acid substitution p.Arg297Gln, which involves the second of the critical arginines in the S4 voltage sensor. This mutation is characterized as pathogenic by five different prediction programs. RFLP analysis and Sanger sequencing confirmed the presence of the mutation in the patient, but not in his parents, characterizing it as de novo. We believe that this discovery characterizes a new channelopathy.


Asunto(s)
Ataxia/genética , Canalopatías/genética , Epilepsias Mioclónicas/genética , Canal de Potasio Kv.1.2/genética , Sustitución de Aminoácidos , Animales , Ataxia/patología , Canalopatías/patología , Epilepsias Mioclónicas/patología , Exoma , Heterocigoto , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactante , Masculino , Ratones , Mutación
5.
Eur J Vasc Endovasc Surg ; 37(1): 87-91, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18993088

RESUMEN

OBJECTIVES: To identify predictive factors causing mortality in patients with injuries to the portal (PV) and superior mesenteric veins (SMV). DESIGN: Retrospective analysis of prospectively collected data. MATERIALS AND METHODS: Adults admitted with blunt or penetrating PV and SMV injuries at an academic level I trauma center during a 20-year period. RESULTS: Of 26,387 major trauma victims admitted from 1987 through 2006, 26 sustained PV or SMV injuries (PV=15, SMV=11). Mechanism of injury was penetrating in 19 (73%) and 20 were in shock. Active hemorrhage occurred in 21. Most patients had associated injuries (2.9+/-1.8/patient). Mean Injury Severity Score (ISS) was 27.8+/-16.8. All PV injuries underwent suture repair and 27% of SMV injuries were ligated. Overall mortality was 46% (PV=47%, SMV=45%). Stab wounds had a lower mortality (31%) compared to gunshot wounds (67%) and blunt injuries (57%). Nonsurvivors had a higher ISS (35.8 vs. 20.9; p=0.02), more associated injuries (3.7 vs. 2.2; p=0.02), were older, and had active hemorrhage. Active hemorrhage (p=0.04) was independently related to death while shock on admission (odds ratio=6.1, p=0.61) trended toward higher mortality. CONCLUSION: Despite improvements in trauma care, mortality of PV and SMV injuries remains high. Shock, active hemorrhage, and associated injuries were predictive of increased mortality.


Asunto(s)
Traumatismos Abdominales/mortalidad , Venas Mesentéricas/lesiones , Vena Porta/lesiones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Heridas no Penetrantes , Heridas Penetrantes , Adulto Joven
6.
Scand J Surg ; 98(3): 135-42, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19919917

RESUMEN

Lower gastrointestinal bleeding is a common cause for hospital admission that results in significant morbidity and mortality. After initial resuscitation of the patient, the diagnosis and treatment of lower gastrointestinal bleeding remains a challenge for acute care surgeons. Identifying the source of bleeding can be difficult since many patients bleed intermittently or stop bleeding spontaneously. It is therefore important for the acute care surgeon to be familiar with the different diagnostic and therapeutic modalities and their advantages and disadvantages in order to guide the management of the acutely bleeding patient. This review summarizes the current methods available for the diagnosis and treatment of acute lower gastrointestinal bleeding and proposes an algorithm for the management of these patients.


Asunto(s)
Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/terapia , Enfermedades Intestinales/diagnóstico , Enfermedades Intestinales/terapia , Enfermedad Aguda , Algoritmos , Colonoscopía , Árboles de Decisión , Diagnóstico por Imagen , Hemorragia Gastrointestinal/etiología , Humanos , Enfermedades Intestinales/complicaciones
9.
World J Emerg Surg ; 11: 25, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27307785

RESUMEN

Acute calculus cholecystitis is a very common disease with several area of uncertainty. The World Society of Emergency Surgery developed extensive guidelines in order to cover grey areas. The diagnostic criteria, the antimicrobial therapy, the evaluation of associated common bile duct stones, the identification of "high risk" patients, the surgical timing, the type of surgery, and the alternatives to surgery are discussed. Moreover the algorithm is proposed: as soon as diagnosis is made and after the evaluation of choledocholitiasis risk, laparoscopic cholecystectomy should be offered to all patients exception of those with high risk of morbidity or mortality. These Guidelines must be considered as an adjunctive tool for decision but they are not substitute of the clinical judgement for the individual patient.

11.
Bioresour Technol ; 185: 276-84, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25780903

RESUMEN

This work aimed to study both the removal of nutrients and pharmaceuticals, namely salicylic acid or paracetamol, from water by the culture of Chlorella sorokiniana. The removal of nutrients was nearly complete at the end of the batch culture; above 70% for nitrates and 89% for phosphates in the semicontinuous culture. The pharmaceuticals removal kinetics were 2.3 times greater for the salicylic acid than paracetamol, reaching volumetric efficiencies above 93% for salicylic acid in the semicontinuous culture. Finally, to separate the microalgae biomass from treated water, metal salts, synthetic polyelectrolytes and a biopolymer were tested as coagulants-flocculants. The best flocculation results were achieved with AlCl3 (95.23% with 200mgg(-1), 1min incubation time). However, given that resulting flocs had different characteristics, flocculants must be chosen on the basis of the subsequent use of the biomass.


Asunto(s)
Chlorella , Aguas Residuales , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Acetaminofén/química , Cloruro de Aluminio , Compuestos de Aluminio/química , Biodegradación Ambiental , Biomasa , Cloruros/química , Floculación , Microalgas , Nitratos/química , Preparaciones Farmacéuticas/análisis , Fosfatos/química , Ácido Salicílico/química
12.
Res Microbiol ; 150(8): 543-53, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10577487

RESUMEN

Due to the scarcity of distinctive biochemical reactions for differentiation of Shigella-Escherichia coli, antigenic analysis has long been used for identification and typing of Shigella isolates. Nevertheless, several intra- and interspecific cross-reactions have been reported to disturb serotyping assays. Shigella serotyping is also occasionally affected by the transition from the smooth (S) form to the rough (R) form. Thus, there is a need for the development of novel robust and discriminating methods for Shigella identification and typing. Characteristically, all genes specifically involved in O-antigen synthesis are clustered in E. coli, Shigella, and Salmonella. Published oligonucleotide sequences complementary to JUMPstart and gene gnd, the conserved flanking sequences upstream and downstream of O-antigen gene clusters, were used to amplify the O-antigen gene cluster of representative strains of each Shigella serotype. A unique, amplified fragment was generally observed for each serotype (size ranging from 6 kbp to 17 kbp). Clearly identifiable and reproducible patterns were obtained for each serotype after MboII digestion of the products, except for S. boydii 12 which showed two distinct patterns, and S. flexneri serotypes 1 to 5 and X and Y which showed a single pattern. A database was built with the Taxotron package allowing automated identification of clinical Shigella isolates to all known serotypes.


Asunto(s)
Proteínas Bacterianas/genética , Antígenos O/genética , Shigella/clasificación , ADN Bacteriano/análisis , Desoxirribonucleasas de Localización Especificada Tipo II , Humanos , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Serotipificación , Shigella/genética , Shigella/aislamiento & purificación
13.
Res Microbiol ; 152(1): 47-55, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11281325

RESUMEN

We describe a MluI ribotyping scheme for Shigella which approaches correlation with serotyping. One hundred and seventeen reference strains and previously serotyped clinical isolates representing the 57 Shigella serotypes and biotypes were included in this study. A total of 51 distinct ribotypes were obtained and a database was built with them. The number of bands composing each ribotype varied from 9 to 15. The fragments ranged in size from 1.6 to 18.8 kbp. One hundred and eleven clinical isolates were successfully identified in a double blind study with standard biochemical/serologic methods, by automatic comparison of their ribotypes with our database using the software Taxotron.


Asunto(s)
Proteínas Bacterianas , Bases de Datos Factuales , Disentería Bacilar/microbiología , Genes de ARNr , Ribotipificación , Shigella/clasificación , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Disentería Bacilar/epidemiología , Escherichia coli/clasificación , Escherichia coli/genética , Humanos , Serotipificación , Shigella/genética , Programas Informáticos
14.
Res Microbiol ; 151(8): 639-54, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11081579

RESUMEN

The precise serotyping of clinical Escherichia coli isolates is a crucial step for diagnostic and epidemiological purposes. Epidemiological knowledge associated with serotyping is so important that no alternative method may be considered if it does not correlate with serotyping. Unfortunately, E. coli are difficult to serotype. Genes specifically involved in O-antigen synthesis are clustered in E. coli, Shigella and Salmonella. Published oligonucleotide sequences complementary to JUMPstart and the gnd gene (the conserved flanking sequences upstream and downstream of O-antigen gene clusters, respectively) were used to amplify the O-antigen gene cluster of representative strains of 148 E. coli O-serogroups. A unique amplified fragment was observed for each serogroup (size ranging from 1.7 to 20 kbp). Clearly identifiable and reproducible O-patterns were obtained for the great majority of O-serogroups after MboII digestion of amplified products. The number of bands composing each pattern varied from five to 25. A database was built with the patterns obtained. A total of 147 O-patterns were obtained. Thirteen O-serogroups were subdivided into different O-patterns. However, each of 13 other O-patterns was shared by two or more O-serogroups. 0-serogroups of clinical isolates were deduced accurately from O-patterns in all cases, even for some rough or nonagglutinating isolates. The restriction method (rfb-RFLP) may prove to be better than serotyping since 100% of strains are typable, which is not the case with serotyping.


Asunto(s)
Proteínas Bacterianas/genética , Escherichia coli/genética , Familia de Multigenes , Antígenos O/genética , Polimorfismo de Longitud del Fragmento de Restricción , Escherichia coli/clasificación , Serotipificación , Shigella/genética
15.
Shock ; 4(1): 45-9, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7552777

RESUMEN

In recent years, hypertonic, and hyperoncotic fluids have been examined for their potential to replace conventional isotonic fluids. This study describes the effects of commonly used intravenous fluids on immune function. The action of increased concentrations of hypertonic saline (HTS), hypertonic saline-dextran (HSD), dextran (Dx), albumin (ALB), and hydroxyethylstarch (HET) on in vitro proliferation of phytohemagglutinin-stimulated normal and prostaglandin E2-suppressed human peripheral blood mononuclear cells was tested. At clinically relevant levels, HTS, HSD (20-40 mM hypertonicity), and ALB (2.5 mg/mL) enhanced T-cell proliferation by 65, 75, and 70%, respectively. Dx and HET had little effect. HTS also reversed prostaglandin E2-suppressed (10 ng/mL) T-cell proliferation to normal levels, and HSD enhanced T-cell proliferation by 40%, in contrast to Dx, ALB, and HET which had minimal effects. The results suggest that hypertonic/hyperoncotic solutions might improve prostaglandin-mediated suppression of T-cell function in patients and may be a useful adjunct to reduce the risk of infection.


Asunto(s)
Albúminas/farmacología , Dextranos/farmacología , Dinoprostona/farmacología , Derivados de Hidroxietil Almidón/farmacología , Solución Salina Hipertónica/farmacología , Linfocitos T/efectos de los fármacos , Adulto , Análisis de Varianza , División Celular/efectos de los fármacos , Células Cultivadas , Humanos , Masculino , Concentración Osmolar , Linfocitos T/citología
16.
Shock ; 14(6): 594-8, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11131907

RESUMEN

Previous reports have shown beneficial effects of pentoxifylline (PTX) and hypertonic saline (HS) in the treatment of hemorrhagic shock. We compared the effects of these solutions to those of conventional lactated Ringer's (LR) treatment on bacterial translocation (BT), lung injury and total and differential cell count in the bronchoalveolar lavage fluid (BAL) after hemorrhagic shock. Rats (280-330 g) were bled to a MAP of 35 mmHg for 1 h and then randomized into 4 groups: LR (3x shed blood); HS (7,5% NaCl, 4 mL/kg); LR+PTX (25 mg/kg) and SHAM (no shock, no treatment). Additionally, total shed blood was reinfused. At 24 h lung injury was analyzed by a pathologist blinded to the groups, and a score was calculated. BT was determined by microbiological cultures of mesenteric lymph node complex. BAL was performed on a separate set of animals that received the same treatments. Lung score was significantly higher in LR group (11.5+/-1.4) as compared to HS (6.8+/-0.9), and PTX treated animals (7.2+/-0.9). The percentage of neutrophils in the BAL of LR animals (15.8%) was also significantly higher as compared with HS (5.25%) and PTX groups (9.72%). BT was noted in 50% of rats for LR group, 30% for PTX, 10% for HS and 0% for sham group. HS and PTX reduced BT and lung injury after hemorrhage. Attenuation of lung injury could be the result of less neutrophil infiltration into the lungs of HS and PTX treated animals. LR resuscitation caused pronounced lung injury and BT.


Asunto(s)
Lesión Pulmonar , Pulmón/microbiología , Pentoxifilina/uso terapéutico , Solución Salina Hipertónica/administración & dosificación , Choque Hemorrágico/terapia , Animales , Bacterias/aislamiento & purificación , Pulmón/efectos de los fármacos , Masculino , Ratas , Ratas Wistar , Choque Hemorrágico/complicaciones , Choque Hemorrágico/tratamiento farmacológico , Vasodilatadores/administración & dosificación
17.
Shock ; 8(4): 235-41, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9329123

RESUMEN

Hypertonic saline (HS) resuscitation has recently gained attention from trauma physicians because it may benefit the immune system of trauma patients. We have found that HS augments in vitro and in vivo immune function of healthy T-cells. In addition, HS restored the function of suppressed T-cells in vitro and in vivo and reduced immunosuppression after hemorrhage, protecting mice from subsequent sepsis. These effects of HS are based on its direct influence on cellular signaling events through specific signaling pathway(s) that include protein tyrosine kinase and mitogen-activated protein kinase p38 activation. HS provides a costimulatory signal that enhances the proliferation of activated T-cells. HS may be able to substitute signals lost through blockage as a result of trauma induced suppressive factors, thereby restoring the function of suppressed T-cells. Although further work is needed to determine the optimal conditions and possible risks of HS resuscitation, the data presented in this short review of our recent work shed a favorable light on HS as a simple but effective tool to modulate cellular immune function after trauma.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Resucitación/métodos , Solución Salina Hipertónica/uso terapéutico , Heridas y Lesiones/tratamiento farmacológico , Heridas y Lesiones/inmunología , Animales , Humanos
18.
Shock ; 9(3): 164-70, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9525322

RESUMEN

UNLABELLED: Hypertonic saline (HS) resuscitation after hemorrhage and sepsis has been shown to markedly reduce the development of lung injury in animals, compared with traditional resuscitation with lactated Ringer's (LR). These experiments examined the effect of HS on lung injury after hemorrhage without sepsis. The effects of HS and LR resuscitation on neutrophil trafficking, neutrophil adhesion, and neutrophil oxidative burst were studied. METHODS: BALB/c mice were hemorrhaged to a mean arterial pressure of 40 torr for 1 h. Animals were resuscitated with shed blood and either 4 mL/kg of 7.5% HS or LR in twice the volume of the shed blood. Lung histology was examined 24 h after hemorrhage. Lung myeloperoxidase content and bronchoalveolar lavage fluid neutrophil counts were obtained. Peripheral blood smears were obtained to determine the neutrophil percentage. Peripheral blood neutrophil CD11b expression and neutrophil H2O2 production were assayed by flow cytometry. RESULTS: HS animals had less lung injury than LR animals. The mean myeloperoxidase activity in HS versus LR animals was 1.79+/-1.33 U/100 mg versus 3.0+/-1.33 U/100 mg, respectively. The percentage of neutrophils in the bronchoalveolar lavage fluid of HS animals (3.8%+/-.8) was significantly less than that of LR animals (10.8%+/-2.1). This corresponded to a significantly higher peripheral blood neutrophil count in HS animals compared with LR animals, 41% vs. 20%, respectively. There was no difference in neutrophil expression of the CD11b integrin between the HS and LR groups. The neutrophils of LR animals had basal H2O2 production that was 107% greater than that of controls; HS suppressed this hemorrhage-induced activation by > 60%. HS resuscitation after hemorrhagic shock protects against the development of lung injury. This protection is due, in part, to suppression of the hemorrhage-induced neutrophil oxidative burst. HS resuscitation offers immunomodulatory potential after hemorrhagic shock.


Asunto(s)
Lesión Pulmonar , Activación Neutrófila/efectos de los fármacos , Resucitación/métodos , Solución Salina Hipertónica/farmacología , Choque Hemorrágico/complicaciones , Animales , Líquido del Lavado Bronquioalveolar/citología , Adhesión Celular/efectos de los fármacos , Diferenciación Celular , Peróxido de Hidrógeno/metabolismo , Recuento de Leucocitos , Pulmón/patología , Antígeno de Macrófago-1/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Neutrófilos/inmunología , Neutrófilos/metabolismo , Peroxidasa/metabolismo , Estallido Respiratorio/efectos de los fármacos , Choque Hemorrágico/tratamiento farmacológico
19.
J Med Microbiol ; 44(2): 105-9, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8642570

RESUMEN

In order to develop a model for the study of gastric spiral bacteria, and based on the observation that Wistar rats do not carry urease-positive spiral bacteria in their gastric mucosa, mucus from a pig naturally colonised by 'Gastrospirillum suis' (an organism with I6S rDNA 99.5% similar to that of 'G. hominis' type 1), was inoculated into 35 Wistar rats (test group). Fourteen rats were given mucus taken from 'G. suis'-negative swine (control group). Five test animals and two controls were killed 1, 2, 4, 8, 12, 26, and 52 weeks after inoculation. 'G. suis' was observed in the antral mucosa of all test rats but not in the gastric mucosa of any control animal. The number of organisms was high from the beginning of the infection and increased over the period of observation. The bacteria were seen deep in the gastric antral glands, especially in the advanced stages of infection. Histological study of two test rats killed 1 week after inoculation and of all rats killed from the second week after infection revealed the presence of a mild inflammatory response characterised by the infiltration of small numbers of mononuclear cells and scarce polymorphonuclear cells in the subglandular region of the antral mucosa. Lymphoid aggregates were observed in the antral mucosa of rats killed from 1 month onwards, and increased in size and number over the period of infection. Control animals did not have any histological changes in the gastric mucosa. The natural transmission of the bacterium from rat to rat was also investigated. Five non-inoculated animals (contact group) and rats of the test group were maintained in the same cage and killed after 12 weeks. Two animals of the contact group showed slight infiltration of mononuclear cells in the antral mucosa, although they were not colonised by 'G. suis', a finding that supports the hypothesis of faecal-oral transmission of gastric Helicobacter spp. This animal model could be used not only to understand different aspects of the relationship between spiral bacteria and the gastric mucosa but also to obtain large numbers of the organism, free from other spiral bacteria to study some of its properties.


Asunto(s)
Infecciones Bacterianas/microbiología , Helicobacter/aislamiento & purificación , Animales , Infecciones Bacterianas/patología , Modelos Animales de Enfermedad , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Ratas , Ratas Wistar
20.
Chem Commun (Camb) ; (1): 112-3, 2003 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-12610991

RESUMEN

One-electron oxidation of 1,3,5-triazines is observed with both excited uranyl ion (*UO2(2+)) and sulfate radical anion (SO4.-) in aqueous solution, but not with Tl2+, indicating that the standard reduction potentials E degree of 1,3,5-triazine radical cations are = 2.3 +/- 0.1 V vs. NHE, consistent with theoretical calculations; this suggests that if triazines inhibit electron transfer during photosynthesis, they would need to act on the reductive part of the electron transport chain.

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