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1.
Opt Express ; 32(4): 5252-5260, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38439257

RESUMEN

Although Sc doped AlN (ScAlN) has been used extensively in micro-electro-mechanical systems (MEMS) devices and more recently in optical devices, there have not been thorough studies of its intrinsic optical losses. Here we explore the optical losses of the Sc0.30Al0.70N waveguide system by observing racetrack resonator waveguide quality factors. Using a partial physical etch, we fabricate waveguides and extract propagation losses as low as 1.6 ± 0.3 dB/cm at wavelengths around 1550 nm, mostly dominated by intrinsic material absorption from the Sc0.30Al0.70N thin film layer. The highest quality factor of the resonators was greater than 87,000. The propagation loss value is lower than any value previously published and shows that this material can be broadly used in optical modulators without significant loss.

2.
J Cyst Fibros ; 22(5): 941-943, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37045685

RESUMEN

We present the case of a girl (now 11 years and 9 months old) with cystic fibrosis (F508del homozygote), who developed pruritic rash and urticaria six days after the first dose of the CFTR modulators lumacaftor/ivacaftor. The treatment was paused and had to be interrupted due to an immediate recurrence of the urticarial rash after rechallenge. We developed a drug desensitization protocol, aligned to protocols used for desensitization against oral antibiotics. In contrast to other published protocols, it was performed by rapidly increasing the dose of lumacaftor/ivacaftor granulate at 15 min intervals. The medication was continued without interruption, the rash did not reappear during follow-up of two years. This drug desensitization protocol provides a potential new therapeutic option for patients with drug hypersensitivity reactions to CFTR modulators, especially when there are no alternative treatments. Lumacaftor/ivacaftor is available as granulate, doses can be titrated during desensitization and used for long-term treatment.


Asunto(s)
Fibrosis Quística , Exantema , Femenino , Humanos , Lactante , Fibrosis Quística/diagnóstico , Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/uso terapéutico , Volumen Espiratorio Forzado , Combinación de Medicamentos , Aminofenoles/uso terapéutico , Aminopiridinas/uso terapéutico , Benzodioxoles/uso terapéutico , Tolerancia a Medicamentos , Exantema/inducido químicamente , Exantema/tratamiento farmacológico , Mutación
3.
Immunother Adv ; 3(1): ltac023, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36789295

RESUMEN

Introduction: Current treatments for asthma help to alleviate clinical symptoms but do not cure the disease. In this study, we explored a novel therapeutic approach for the treatment of house dust mite allergen Der p 1induced asthma by aiming to eliminate specific population of B-cells involved in memory IgE response to Der p 1. Materials and Methods: To achieve this aim, we developed and evaluated two different proDer p 1-based fusion proteins; an allergen-toxin (proDer p 1-ETA) and an allergen-drug conjugate (ADC) (proDer p 1-SNAP-AURIF) against Der p 1 reactive hybridomas as an in vitro model for Der p 1 reactive human B-cells. The strategy involved the use of proDer p 1 allergen as a cell-specific ligand to selectively deliver the bacterial protein toxin Pseudomonas exotoxin A (ETA) or the synthetic small molecule toxin Auristatin F (AURIF) into the cytosol of Der p 1 reactive cells for highly efficient cell killing. Results: As such, we demonstrated recombinant proDer p 1 fusion proteins were selectively bound by Der p 1 reactive hybridomas as well as primary IgG1+ B-cells from HDM-sensitized mice. The therapeutic potential of proDer p 1-ETA' and proDer p 1-SNAP-AURIF was confirmed by their selective cytotoxic activities on Der p 1 reactive hybridoma cells. The allergen-toxin demonstrated superior cytotoxic activity, with IC50 values in the single digit nanomolar value, compared to the ADC. Discussions: Altogether, the proof-of-concept experiments in this study provide a promising approach for the treatment of patients with house dust mite-driven allergic asthma.

4.
N Z Vet J ; 70(6): 340-348, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35968551

RESUMEN

CASE HISTORY: A 3-year-old, intact female mixed-breed dog, weighing 7 kg, was presented with generalised swelling of the tongue, leading to impaired deglutition and episodes of dyspnoea. From the age of 2 years, the dog had been under immunosuppressive therapy due to atopic dermatitis. CLINICAL FINDINGS AND TREATMENT: Multiple nodular lesions at the apex of the tongue were noted as well as mandibular and retropharyngeal lymph node enlargement. Serum biochemistry results showed inflammatory changes. The results of several biopsies taken over 7 months indicated persistent pyogranulomatous and necrotising glossitis despite ongoing antimicrobial treatment, first with amoxicillin/clavulanic acid and then pradofloxacin. No foreign material, acid-fast bacteria or fungal hyphae were detected throughout. The final diagnosis of Mycobacterium avium subsp. hominissuis (Mah) was reached after PCR and bacterial culture were carried out on the third biopsy sample. Therapy was initiated with rifampicin, clarithromycin and doxycycline, leading to complete remission of the lesions. DIAGNOSIS: Severe chronic pyogranulomatous and necrotising glossitis associated with infection by Mah. CLINICAL RELEVANCE: This report describes challenges in the diagnosis and therapy of a localised Mah infection in an iatrogenically immunocompromised dog. Successful treatment was only achieved with a specific combination of antibiotics administered long-term. ABBREVIATIONS: AF: Acid-fast; ALP: Alkaline phosphatase; CT: Computed tomography; MAC: Mycobacterium avium complex; Mah: Mycobacterium avium subsp. hominissuis.


Asunto(s)
Enfermedades de los Perros , Glositis , Fosfatasa Alcalina , Amoxicilina , Animales , Antibacterianos , Claritromicina , Ácido Clavulánico , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/tratamiento farmacológico , Perros , Doxiciclina , Femenino , Glositis/diagnóstico , Glositis/tratamiento farmacológico , Glositis/veterinaria , Inmunomodulación , Mycobacterium , Mycobacterium avium , Rifampin
5.
Nanotechnology ; 31(44): 445204, 2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-32647099

RESUMEN

Despite being known of for decades, the actual realization of memory devices based on the memristive effect is progressing slowly, due to processing requirements and the need for exotic materials which are not compatible with today's complementary-metal-oxide-semiconductor (CMOS) technology. Here, we report an experimental study on a Ge quantum wire device featuring distinct signatures of memristive behavior favorable for integration in CMOS platform technology. Embedding the quasi-1D Ge quantum wire into an electrostatically modulated back-gated field-effect transistor, we demonstrate that individual current transport channels can be addressed directly by controlling the surface trap assisted electrostatic gating. The resulting quantization of the current represents the ultimate limit of memristors with practically zero off-state current and low footprint. In addition, the proposed device has the advantage of non-destructive successive reading cycles capability. Importantly, our findings provide a framework towards fully CMOS compatible ultra-scaled Ge based memristors.

6.
Med Eng Phys ; 81: 125-129, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32473841

RESUMEN

Physical activity (PA) is highly recommended in the management of most chronic diseases. For these patients, the smart electric bicycle can be effective to improve adherence to this behavior. The E-bike used in this study (called VELIS) has an innovative onboard technology that allows for subject monitoring and the engine power is designed to adapt to the user's abilities. A prerequisite for the use of the VELIS with patients is to initially carry out a pilot study on healthy subjects. The objective was to evaluate the impact of the customizable settings on physiological parameters and to ensure this prototype's efficiency and safety of use. Twelve healthy participants with various profiles (physical condition, used to cycling or not) were included. They have completed four times a 14 km itinerary with various settings of the VELIS. We recorded GPS data, heart rate and perceived exertion. Based on exercise intensity, we confirm that riding an E-bike should be considered as a physical activity. Safety of the participants is ensured by the engine brake. Recordings show that it took between 1 and 3 min for the novice to become familiar with the VELIS and to get optimal assistance. The main finding of this pilot study confirms that VELIS is an easy to use and secure tool to make PA approachable, whatever the level of training in healthy subjects.


Asunto(s)
Ciclismo , Electricidad , Electrónica , Ejercicio Físico , Adulto , Anciano , Ciclismo/educación , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
7.
J Comp Pathol ; 172: 1-4, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31690406

RESUMEN

Mycobacterium bovis is the main agent of bovine tuberculosis, but has also zoonotic potential. An 8-month-old female domestic shorthaired cat imported from Ukraine developed wound complications after abdominal surgery. A second surgery performed in Germany showed a focal, partly cystic mass within the mesentery. Despite antimicrobial treatment, the cat did not recover and was humanely destroyed. Grossly, several abdominal lymph nodes were enlarged. Histopathology revealed a mild to moderate, multifocal, granulomatous to pyogranulomatous, partially necrotizing inflammation, most prominent in the abdominal cavity. Within the lesions there were acid-fast bacilli within the cytoplasm of macrophages demonstrated by Ziehl-Neelsen staining. Further investigations revealed M. bovis SB0950 in the affected tissues.


Asunto(s)
Mycobacterium bovis/aislamiento & purificación , Herida Quirúrgica/microbiología , Tuberculosis Bovina/microbiología , Animales , Enfermedades de los Gatos/microbiología , Gatos , Bovinos , Femenino , Ganglios Linfáticos/microbiología , Ganglios Linfáticos/patología , Macrófagos/microbiología , Macrófagos/patología , Herida Quirúrgica/complicaciones , Zoonosis/microbiología
8.
BMC Res Notes ; 12(1): 311, 2019 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-31151479

RESUMEN

OBJECTIVES: The objective of this study was to establish transcriptome assemblies of Festulolium hybrids under salt stress, and identify genes regulated across the hybrids in response to salt stress. The development of transcriptome assemblies for Festulolium hybrids and cataloguing of genes regulated under salt stress will facilitate further downstream studies. RESULTS: Plants were grown at three salt concentrations (0.5%, 1% and 1.5%) and phenotypic and transcriptomic data was collected. Salt stress was confirmed by progressive loss of green leaves as salt concentration increased from 0 to 1.5%. We generated de-novo transcriptome assemblies for two Festulolium pabulare festucoid genotypes, for a single Festulolium braunii genotype, and a single F. pabulare loloid genotype. We also identified 1555 transcripts that were up regulated and 1264 transcripts that were down regulated in response to salt stress in the Festulolium hybrids. Some of the identified transcripts showed significant sequence similarity with genes known to be regulated during salt and other abiotic stresses.


Asunto(s)
Festuca/genética , Regulación de la Expresión Génica de las Plantas , Hibridación Genética/genética , Lolium/genética , Estrés Salino/genética , Transcriptoma , Festuca/crecimiento & desarrollo , Perfilación de la Expresión Génica , Genes de Plantas/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Lolium/crecimiento & desarrollo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Transcripción Genética
9.
Nanoscale ; 10(41): 19443-19449, 2018 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-30311606

RESUMEN

Metastable germanium-tin alloys are promising materials for optoelectronics and optics. Here we present the first electrical characterization of highly crystalline Ge0.81Sn0.19 nanowires grown in a solution-based process. The investigated Ge0.81Sn0.19 nanowires reveal ohmic behavior with resistivity of the nanowire material in the range of ∼1 × 10-4Ω m. The temperature-dependent resistivity measurements demonstrate the semiconducting behavior. Moreover, failure of devices upon heating to moderate temperatures initiating material degradation has been investigated to illustrate that characterization and device operation of these highly metastable materials have to be carefully conducted.

10.
Physiol Res ; 67(Suppl 1): S247-S255, 2018 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-29947544

RESUMEN

The first trimester of pregnancy is characterized by continuous proliferation, invasion and differentiation of cytotrophoblasts. These processes are precisely controlled both, in space and time by molecules such as endothelin-1 (ET-1). ET-1 is expressed in human first trimester trophoblast and is known to stimulate cytotrophoblast proliferation through endothelin A and B receptor subtypes (ET(A) and ET(B)), and cytotrophoblast invasion through ET(B). However, temporal changes of the ET system during the first trimester of pregnancy have not been previously studied. This study tested the hypothesis that ET-1 release, ET(A) and ET(B) expression are increased towards the end of the first trimester of pregnancy (weeks 10-12 vs. weeks 6-9), resulting in increased cytotrophoblast proliferation and invasion. Tissue samples were obtained from 17 surgical pregnancy interruptions (week 6-9: n=9; week 10-12: n=8). After cytotrophoblast isolation, the invasive and proliferative phenotypes were immune-separated by an alpha(6)-integrin antibody. Both proliferative and invasive cytotrophoblasts were cultured separately on plastic or Matrigel for 24 h. ET-1 release into the culture medium of both cytotrophoblast subtypes was measured by radioimmunoassay. ET(A) and ET(B) mRNA expression was measured by RT-PCR, and the ET-1 effect on cytotrophoblast proliferation and invasion was determined using proliferation and invasion assays, respectively. ET-1 release increased from early to late first trimester of pregnancy in both proliferative (1.8-4.5 fold) and invasive cytotrophoblasts (9.3-28 fold), especially when cultured on Matrigel. This was paralleled by less ET(B) mRNA on invasive cytotrophoblasts independent of the time period in first trimester, whereas ET(A) expression was similar on proliferative an invasive cytotrophoblasts. Proliferation and invasion of cytotrophoblasts under control conditions decreased from early to late first trimester. ET-1 stimulated both processes at both periods with the most pronounced effect (7-fold) on invasion in late first trimester. The ET-1/ET-receptor system changes between weeks 6-9 and 10-12 in pregnancy. Our data suggest an autocrine and endocrine ET-1 effect, which is stronger in late than in early first trimester of pregnancy paralleled by different stimulatory effects on trophoblast invasion and proliferation. In general, this suggests time as an additional effector of the critical processes governing placental development in the first trimester of human pregnancy.


Asunto(s)
Endotelina-1/metabolismo , Placenta/citología , Placenta/metabolismo , Primer Trimestre del Embarazo/metabolismo , Receptor de Endotelina A/metabolismo , Trofoblastos/metabolismo , Proliferación Celular/fisiología , Células Cultivadas , Femenino , Humanos , Embarazo , Factores de Tiempo
11.
Int J Med Microbiol ; 308(7): 899-911, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29937390

RESUMEN

In 2011, Germany was struck by the largest outbreak of hemolytic uremic syndrome. The highly virulent E. coli O104:H4 outbreak strain LB226692 possesses a blended virulence profile combining genetic patterns of human adapted enteroaggregative E. coli (EAEC), rarely detected in animal hosts before, and enterohemorrhagic E. coli (EHEC), a subpopulation of Shiga toxin (Stx)-producing E. coli (STEC) basically adapted to the ruminant host. This study aimed at appraising the relative level of adaptation of the EAEC/EHEC hybrid strain LB226692 to humans and cattle. Adherence and invasion of the hybrid strain to intestinal (jejunal and colonic) epithelial cells (IEC) of human and bovine origin was compared to that of E. coli strains representative of different pathovars and commensal E. coli by means of light and electron microscopy and culture. Strain-specific host gene transcription profiles of selected cytokines and chemokines as well as host-induced transcription of bacterial virulence genes were assessed. The release of Stx upon host cell contact was quantified. The outbreak strain's immunomodulation was assessed by cultivating primary bovine macrophages with conditioned supernatants from IEC infection studies with E. coli, serving as model for the innate immunity of the bovine gut. The outbreak strain adhered to IEC of both, human and bovine origin. Electron microscopy of infected cells revealed the strain's particular affinity to human small IEC, in contrast to few interactions with bovine small IEC. The outbreak strain possessed a high-level of adhesive power, similar to human-associated E. coli strains and in contrast to bovine-associated STEC strains. The outbreak strain displayed a non-invasive phenotype, in contrast to some bovine-associated E. coli strains, which were invasive. The outbreak strain provoked some pro-inflammatory activity in human cells, but to a lower extent as compared to other pathotypes. In contrasts to bovine-associated E. coli strains, the outbreak strain induced marked pro-inflammatory activity when interacting with bovine host cells directly (IEC) and indirectly (macrophages). Among stx2-positive strains, the human-pathogenic strains (LB226692 and EHEC strain 86-24) released higher amounts of Stx compared to bovine-associated STEC. The findings imply that the outbreak strain is rather adapted to humans than to cattle. However, the outbreak strain's potential to colonize IEC of both host species and the rather mixed reaction patterns observed for all strains under study indicate, that even STEC strains with an unusual genotype as the EHEC O104:H4 outbreak strain, i.e. with an EAEC genetic background, may be able to conquer other reservoir hosts.


Asunto(s)
Infecciones por Escherichia coli/epidemiología , Escherichia coli O104/patogenicidad , Síndrome Hemolítico-Urémico/epidemiología , Inflamación/inmunología , Mucosa Intestinal/microbiología , Animales , Bovinos , Línea Celular , Chlorocebus aethiops , Colon/citología , Colon/microbiología , Brotes de Enfermedades , Células Epiteliales/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli O104/inmunología , Escherichia coli O104/aislamiento & purificación , Alemania/epidemiología , Síndrome Hemolítico-Urémico/microbiología , Interacciones Huésped-Patógeno/fisiología , Humanos , Mucosa Intestinal/citología , Yeyuno/citología , Yeyuno/microbiología , Macrófagos/microbiología , Toxina Shiga/biosíntesis , Células Vero , Virulencia
12.
Mult Scler Relat Disord ; 22: 139-140, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29684788

RESUMEN

The most common adverse events associated with the monoclonal antibody alemtuzumab are infusion associated reactions and secondary autoimmune disease. Respiratory complications are unusual following treatment with alemtuzumab, but can be precipitated by an infectious cause. We describe a case of a sub-acute steroid responsive non-infectious pneumonitis affecting a 51 year old woman, who presented one month after initiation of therapy for multiple sclerosis with alemtuzumab.


Asunto(s)
Alemtuzumab/efectos adversos , Disnea/etiología , Factores Inmunológicos/efectos adversos , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Neumonía/etiología , Alemtuzumab/uso terapéutico , Diagnóstico Diferencial , Disnea/diagnóstico , Disnea/tratamiento farmacológico , Femenino , Humanos , Factores Inmunológicos/uso terapéutico , Persona de Mediana Edad , Neumonía/diagnóstico , Neumonía/tratamiento farmacológico
13.
Transbound Emerg Dis ; 65(3): 746-757, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29322645

RESUMEN

On the Mediterranean island of Corsica, cohabitation between sympatric domestic pigs and Eurasian wild boar (Sus scrofa) is common and widespread and can facilitate the maintenance and dissemination of several pathogens detrimental for the pig industry or human health. In this study, we monitored a population of free-ranging domestic pigs reared in extensive conditions within a 800-ha property located in Central Corsica which was frequently visited by a sympatric population of wild boar between 2013 and 2015. We used GPS collars to assess evidence of a spatially shared environment. Subsequently, we analysed by PFGE of XbaI-restricted DNA if those populations shared faecal Escherichia coli clones that would indicate contact and compared these results with those collected in a distant (separated by at least 50 km) population of wild boar used as control. Results showed that one of eight wild boars sampled in the study area shed E. coli XbaI clones identical to clones isolated from domestic pig sounders from the farm, while wild boar populations sampled in distant parts of the study area shared no identical clone with the domestic pigs monitored. Interestingly, within the sampled pigs, two identical clones were found in 2013 and in 2015, indicating a long-time persisting colonization type. Although the method of isolation of E. coli and PFGE typing of the isolates requires intensive laboratory work, it is applicable under field conditions to monitor potential infectious contacts. It also provides evidence of exchange of microorganisms between sympatric domestic pigs and wild boar populations.


Asunto(s)
Infecciones por Escherichia coli/transmisión , Escherichia coli/aislamiento & purificación , Heces/microbiología , Sus scrofa/microbiología , Animales , Biomarcadores Ambientales , Francia , Humanos
15.
Herzschrittmacherther Elektrophysiol ; 28(2): 212-218, 2017 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-28488109

RESUMEN

Ventricular tachycardias (VT) in patients with structural heart diseases have predominantly a scar-associated reentry mechanism so that substrate-based ablation approaches also have to be used in nearly all procedures. In many VT cases-especially in nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy-a critical epicardial substrate can be identified as an essential component of the reentry circuit so that for the ablation-based modification of the substrate in these cases an epicardial approach is necessary. In cases of redo-VT ablation procedures in ischemic cardiomyopathy (after a previously endocardial ablation), an epicardial approach should also be considered. There are also cases in whom no endocardial substrate can be identified and an isolated epicardial substrate can be identified. Worldwide epicardial VT ablations are usually performed after gaining epicardial access using subxyphoidal puncture. The results of recent studies show a higher efficiency with stabilization of cardiac rhythm and reduction of recurrent VT episodes (about 70% event-free survival at the 2­year follow-up) after endo-plus epicardial substrate modification. In electrical storm cases, an early epicardial VT ablation approach also appears to be relevant, especially in NICM. Epicardial instrumentation and ablation represents a complex procedure which should only be performed in experienced centers with cardiac surgery back-up. In these experienced centers, the complications rate is less than 5%.


Asunto(s)
Ablación por Catéter , Pericardio/cirugía , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Cardiomiopatías/diagnóstico , Cardiomiopatías/fisiopatología , Cardiomiopatías/cirugía , Cicatriz/diagnóstico , Cicatriz/fisiopatología , Cicatriz/cirugía , Angiografía Coronaria , Mapeo Epicárdico , Adhesión a Directriz , Humanos , Imagen por Resonancia Magnética , Pericardio/fisiopatología , Reoperación , Taquicardia por Reentrada en el Nodo Atrioventricular/diagnóstico , Taquicardia por Reentrada en el Nodo Atrioventricular/fisiopatología , Resultado del Tratamiento
16.
Transbound Emerg Dis ; 64(2): 487-494, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26190581

RESUMEN

Domestic pigs and Eurasian wild boar (Sus scrofa) share several important viral and bacterial pathogens. Therefore, direct and indirect contacts between domestic pigs and wild boar present a risk of pathogen spillover and can lead to long-term perpetuation of infection. Biological indicators could be a powerful tool to understand and characterize contacts between wild boar and domestic pigs. Here, faecal Escherichia coli and Hepatitis E virus (HEV) were explored as potential biological indicators under experimental conditions. The data gained in our pilot study suggest that faecal E. coli can be used as biological indicator of contact between wild boar and domestic pig. For HEV, faecal transmission was also confirmed. However, molecular studies on full-genome basis did not reveal markers that would allow tracing of transmission direction. Based on these promising results, future field studies will especially target the practicability of E. coli microbiome molecular typing as surrogate of contacts at the wildlife-livestock interface.


Asunto(s)
Escherichia coli/aislamiento & purificación , Heces/microbiología , Heces/virología , Virus de la Hepatitis E/aislamiento & purificación , Animales , Infecciones por Escherichia coli/transmisión , Hepatitis E/transmisión , Proyectos Piloto , Sus scrofa/microbiología , Sus scrofa/virología , Porcinos
17.
Vet Microbiol ; 202: 29-37, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27039884

RESUMEN

Prevention of enterohemorrhagic Escherichia coli (EHEC) O157:H7 infections and of their severe clinical sequelae in humans remain to be a current challenge. Administration of bovine lactoferrin (bLF) proved to be effective in clearing EHEC from the bovine intestine, an important EHEC reservoir, suggesting that bLF may also be beneficial in human application against EHEC infections. To estimate the biological safety of this approach, we analyzed the effects of bLF on the main EHEC virulence factor, Shiga toxin (Stx). We quantified the release of Stx 1 and 2 from two O157:H7 EHEC strains (Stx1+Stx2+ and Stx2+ producing, respectively) cultured in the presence of bLF using ELISA assays and assessed cytotoxic effects of bLF and co-cultured EHEC on Vero cells. Effects of bLF on the stability of Stx2 were investigated using western blotting. ELISA results indicate a bLF concentration-dependent decrease of active, cell-free Stx2, but not Stx1 in EHEC cultures. High concentrations (100 and 50mg/ml) of bLF resulted in significantly reduced (p<0.05) metabolic activity rates of Vero cells, whereas a concentration of 10mg/ml bLF was considered non-toxic for Vero cells. At concentrations of 1 or 0.1mg/ml, bLF mitigated the verocytotoxicity of EHEC strains in a co-culture model up to 48h after inoculation. When only colonizing bacteria were taken into account, cytotoxicity could be significantly reduced by 10 and 1mg/ml bLF during 48h. This effect of bLF at least partly results from degradation of the Stx2 receptor-binding B-subunit.


Asunto(s)
Escherichia coli O157/efectos de los fármacos , Lactoferrina/farmacología , Toxina Shiga I/metabolismo , Toxina Shiga/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Escherichia coli O157/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Toxina Shiga/genética , Toxina Shiga I/genética , Células Vero
18.
Sci Rep ; 6: 32812, 2016 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-27600997

RESUMEN

In 2011, a severe outbreak of hemolytic-uremic syndrome was caused by an unusual, highly virulent enterohemorrhagic E. coli (EHEC) O104:H4 strain, which possessed EHEC virulence traits in the genetic background of human-adapted enteroaggregative E. coli. To determine magnitude of fecal shedding and site of colonization of EHEC O104:H4 in a livestock host, 30 (ten/strain) weaned calves were inoculated with 10(10) CFU of EHEC O104:H4, EHEC O157:H7 (positive control) or E. coli strain 123 (negative control) and necropsied (4 or 28 d.p.i.). E. coli O157:H7 was recovered until 28 d.p.i. and O104:H4 until 24 d.p.i. At 4 d.p.i., EHEC O104:H4 was isolated from intestinal content and detected associated with the intestinal mucosa. These results are the first evidence that cattle, the most important EHEC reservoir, can also carry unusual EHEC strains at least transiently, questioning our current understanding of the molecular basis of host adaptation of this important E. coli pathovar.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli O104/fisiología , Animales , Adhesión Bacteriana , Bovinos , Enfermedades de los Bovinos/epidemiología , Brotes de Enfermedades , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Escherichia coli O104/patogenicidad , Heces/microbiología
19.
Artículo en Portugués | LILACS | ID: biblio-883035

RESUMEN

A Pneumonia é a principal causa de morte por doença infecciosa em países subdesenvolvidos.¹ No Brasil, a pneumonia adquirida na comunidade é uma das principais causas de internação por doença. Afeta principalmente homens, com taxas de hospitalização mais elevadas em menores de 5 e maiores de 80 anos.²


Pneumonia is the first cause of death in underdeveloped countries.¹ In Brazil, Community-Acquired Pneumonia is one of the main causes of hospitalization due to disease. It affects mostly males, with higher hospital admission rates in those with less than 5 and more than 80 years old.²


Asunto(s)
Enfermedades Pulmonares , Neumonía/epidemiología
20.
Nanotechnology ; 26(47): 475701, 2015 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-26535785

RESUMEN

Recently, focused electron beam-induced deposition has been employed to prepare functional magnetic nanostructures with potential in nanomagnetic logic and sensing applications by using homonuclear precursor gases like Fe(CO)5 or Co2(CO)8. Here we show that an extension towards the fabrication of bi-metallic compounds is possible by using a single-source heteronuclear precursor gas. We have grown CoFe alloy magnetic nanostructures from the HFeCo3(CO)12 metal carbonyl precursor. The compositional analysis indicates that the samples contain about 80 at% of metal and 10 at% of carbon and oxygen. Four-probe magnetotransport measurements are carried out on nanowires of various sizes down to a width of 50 nm, for which a room temperature resistivity of 43 µΩcm is found. Micro-Hall magnetometry reveals that 50 nm × 250 nm nanobars of the material are ferromagnetic up to the highest measured temperature of 250 K. Finally, the transmission electron microscopy (TEM) microstructural investigation shows that the deposits consist of a bcc Co-Fe phase mixed with a FeCo2 O4 spinel oxide phase with nanograins of about 5 nm diameter.

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