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1.
Indian J Otolaryngol Head Neck Surg ; 75(4): 3353-3363, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38027532

RESUMEN

Biphenotypic sinonasal sarcoma (BSNS) is a rare malignant tumour of the upper nasal cavity and ethmoid sinuses that presents predominantly in middle aged female patients and show a characteristic infiltrative and hypercellular proliferation of spindle cells that demonstrate a specific immunoreactivity. We present three cases with BSNS that had different presenting complaints, either sinonasal or orbital problems, underwent endoscopic surgical treatment and/or radiotherapy and have been disease free on long follow up. A systematic review of all published cases was performed to identify all BSNS cases known at present. BSNS requires prompt and correct diagnosis with accurate surgical resection as well as consideration of radiotherapy. Our three cases confirm the findings of the literature and support that BSNS is an aggressive but treatable malignant disease of the sinonasal tract.

2.
Ear Nose Throat J ; : 1455613221119350, 2022 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-35968558

RESUMEN

Ulcerative necrotic supraglottitis is a rare entity of laryngeal infection leading rapidly in laryngeal necrosis, systematic complications and potentially fatal outcomes. We present a case of a 50-year-old gentleman with ulcerative necrotising supraglottitis and no co-morbidities who presented in Ear Nose and Throat Service in the Accident and Emergency department due to dysphagia and weakness. He was treated with an emergency tracheostomy with neck exploration and washout and received appropriate supporting antibiotic regime. He improved and was eventually decannulated, able to breathe phonate and swallow appropriately. After a thorough review of the literature regarding necrotising infections of the laryngeal cavity, only 7 cases have been reported, all in immunocompromised patients with severe complications. Our case report is the first ulcerative necrotic supraglottitis in a healthy individual who was treated early and aggressively with impressive results.

3.
J Clin Med ; 11(12)2022 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-35743536

RESUMEN

The aim of this study was to evaluate gain and refixation saccades (covert and overt) using a video head impulse test (vHIT) in the horizontal and vertical planes in patients after the onset of unilateral acute vestibular neuritis (AVN). Thirty-five patients were examined in the acute stage of AVN and at follow-up (range, 6-30 months); a control group of 32 healthy subjects also participated. At onset, the mean gain was significantly lower on the affected side in all of the semi-circular canal planes, mainly in the horizontal canal plane, and saccades (covert and overt) were more prevalent in the horizontal compared to the vertical canal planes. Multi-canal affection occurred more frequently (80% for gain, 71% for saccades) than isolated canal affection. At follow-up, which ranged from 6 to 30 months, the gain was recovered in all of the canals (anterior in 50%, horizontal in 42.8%, and posterior canal in 41.1% of cases), while covert and overt saccades were reduced in the horizontal and vertical planes. However, covert saccades were still recorded in a greater proportion (69%) than overt saccades (57%) in the horizontal plane and at a lower rate in the vertical planes. The compensatory mechanisms after AVN mainly involve the horizontal canal, as the refixation saccades-especially covert ones-were more frequently recorded in the horizontal than vertical canals.

4.
Int J Surg Case Rep ; 96: 107286, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35716622

RESUMEN

BACKGROUND: Neurofibromas are benign peripheral nerve sheath tumours, formed by a wide variety of different kinds of cells and matrixes. Airway neurofibromas are extremely rare and minimal cases have been described in the literature. Endoscopic surgical removal is considered challenging due to the infiltrating character of the lesion. CASE PRESENTATION: We describe the clinical case of a gentleman, with a left paraglottic space neurofibroma, who presented with dyspnoea and voice changes. He had his neurofibroma removed endoscopically under general anaesthesia. METHODS: The case was analysed and discussed on this gentleman's presentation. However, the diagnosis was set only after the histology report was released. A literature review was performed to explore presentation and management. CONCLUSION: Neurofibromas have extremely low prevalence in the airway. The size of the benign tumour in our case was impressive and the recovery of the gentleman post-operatively was rapid.

5.
Animals (Basel) ; 11(4)2021 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-33916752

RESUMEN

The aim of the study was to investigate the effect of iron oxide (Fe) and silver (Ag) nanoparticles (NPs) on ram semen. A skim milk extender without antibiotics was used as a diluent of 21 ejaculates (8 rams; 2-3 ejaculates/ram). The groups of control (C; semen without NPs), Fe NPs (3.072 mg Fe3O4/mL semen), and Ag NPs (2.048 mg Ag-Fe/mL semen) were incubated (15 °C; 30 min), and then a magnetic field was used for NPs' removal. Standard microbiological procedures were performed for all groups. Post-treated samples were stored (15 °C) for 24 h, and sperm variables (kinetics by computer assisted sperm analysis (CASA); viability; morphology; HOST; DNA integrity) were evaluated at 6 and 24 h. Semen data were analyzed by a mixed model for repeated measures and microbiological data with Student's t-test for paired samples. At 6 h of storage, VCL and rapid movement-spermatozoa, and at 24 h, total/progressive motility and amplitude of lateral head displacement (ALH) were significantly decreased in group Ag compared to control. In group Fe, progressive/rapid movement-spermatozoa were significantly lower compared to control after 24 h of storage. Only in group Ag was a significant reduction of total bacterial count revealed. In conclusion, the examined Fe NPs demonstrated slight antibacterial effect, while the examined Ag NPs provided higher antibacterial properties accompanied by cytotoxicity.

6.
Toxins (Basel) ; 13(3)2021 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-33668901

RESUMEN

Staphylococcus aureus is the most common mastitis-related pathogen in dairy cattle, goats, and sheep worldwide. However, the population structure and genomic characteristics of mastitis-associated S. aureus in small ruminants are limited. Furthermore, the genotypic and phenotypic characteristics involved in the pathogenicity of S. aureus have been thoroughly defined, yet their association with the severity of mastitis is not fully established. Here, we performed genotyping by pulsed-field gel electrophoresis (PFGE) and spa analyses to assess the genetic diversity and relatedness of 162 S. aureus strains recovered from clinical mastitis (CM) and subclinical mastitis (SCM) cases from goats, sheep, and bovines. PFGE analysis revealed 108 distinguishable pulsotypes and 3 main clusters that comprised isolates from the three host species, while according to spa typing, 32 different spa types were identified. Genotypic analysis revealed a spreading of genetically related or indistinguishable S. aureus strains among ovine, caprine, and bovine farms of distant geographical regions. In total, 28 different staphylococcal enterotoxin (SE) gene profiles were observed, revealing a diverse range of SE genes among isolates. By evaluating the antimicrobial resistance, we found low phenotypic antimicrobial resistance among all ruminant isolates. We also performed multiple correspondence analysis, which indicated that the presence of the sec gene, biofilm production, and high autoaggregation ability are associated with CM cases.


Asunto(s)
Enterotoxinas/genética , Enfermedades de las Cabras/microbiología , Mastitis Bovina/microbiología , Mastitis/veterinaria , Enfermedades de las Ovejas/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/aislamiento & purificación , Animales , Antibacterianos/farmacología , Bovinos , Farmacorresistencia Bacteriana/genética , Femenino , Variación Genética , Genotipo , Enfermedades de las Cabras/diagnóstico , Enfermedades de las Cabras/tratamiento farmacológico , Cabras , Grecia , Mastitis/diagnóstico , Mastitis/tratamiento farmacológico , Mastitis/microbiología , Mastitis Bovina/diagnóstico , Mastitis Bovina/tratamiento farmacológico , Ovinos , Enfermedades de las Ovejas/diagnóstico , Enfermedades de las Ovejas/tratamiento farmacológico , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad , Virulencia
7.
Nanomaterials (Basel) ; 10(8)2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-32784995

RESUMEN

This study examined the effect of Fe3O4 nanoparticles on boar semen. Beltsville thawing solution without antibiotics was used to extend ejaculates from 5 boars (4 ejaculates/boar). Semen samples of control group (C) and group with Fe3O4 (Fe; 0.192 mg/mL semen) were incubated under routine boar semen storage temperature (17 °C) for 0.5 h and nanoparticles were removed by a magnetic field. Before and after treatment, aliquots of all groups were cultured using standard microbiological methods. The samples after treatment were stored (17 °C) for 48 h and sperm parameters (computer-assisted sperm analyzer (CASA) variables; morphology; viability; hypo-osmotic swelling test (HOST); DNA integrity) were evaluated at storage times 0, 24, 48 h. Semen data were analyzed by a repeated measures mixed model and microbial data with Student's t-test for paired samples. Regarding CASA parameters, Fe group did not differ from C at any time point. In group C, total motility after 24 h and progressive motility after 48 h of storage decreased significantly compared to 0 h. In group Fe, linearity (LIN) after 48 h and head abnormalities after 24 h of storage increased significantly compared to 0 h. The microbiological results revealed a significant reduction of the bacterial load in group Fe compared to control at both 24 and 48 h. In conclusion, the use of Fe3O4 nanoparticles during semen processing provided a slight anti-microbiological effect with no adverse effects on sperm characteristics.

8.
Surg Case Rep ; 5(1): 75, 2019 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-31073805

RESUMEN

BACKGROUND: Rectal duplication cysts are rare gastrointestinal congenital duplicate cysts with various clinical presentations that require different management. CASE PRESENTATION: We present a case of a lady with a double rectal duplicate cyst which was found incidentally on a follow-up CT abdomen and pelvis scan. The patient initially had a mucocele excision, and following that, she had a non-contrast CT abdomen and pelvis to investigate post-operative pain. The CT scan revealed a single rectal duplicate cyst. She had a posterior approach excision to have it removed, and only intra-operatively, she was found to have a double rectal duplicate cyst. She had them both removed via a midline incision running from the perineal pigmentation and extending until the coccyx. She had another follow-up CT which showed complete excision of the cysts. CONCLUSIONS: After a thorough review of the literature regarding rectal cysts, there was no mention of a double rectal duplicate cyst. The purpose of this paper is to point out the various potential presentations of a rectal cyst as well as the idea that a double cyst is managed effectively in a similar way as the single one.

9.
J Neurotrauma ; 35(19): 2317-2329, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29463176

RESUMEN

Traumatic brain injury (TBI) induces a neuroinflammatory response resulting in astrocyte and microglia activation at the lesion site. This involves upregulation of neuroinflammatory genes, including chemokines and interleukins. However, so far, there is lack of knowledge on transcription factors (TFs) modulating this TBI-associated gene expression response. Herein, we analyzed activating transcription factor 3 (ATF3), a TF encoding a regeneration-associated gene (RAG) predominantly studied in peripheral nervous system (PNS) injury. ATF3 contributes to PNS axon regeneration and was shown before to regulate inflammatory processes in other injury models. In contrast to PNS injury, data on ATF3 in central nervous system (CNS) injury are sparse. We used Atf3 mouse mutants and a closed-head weight-drop-based TBI model in adult mice to target the rostrolateral cortex resulting in moderate injury severity. Post-TBI, ATF3 was upregulated already at early time points (i.e,. 1-4 h) post-injury in the brain. Mortality and weight loss upon TBI were slightly elevated in Atf3 mutants. ATF3 deficiency enhanced TBI-induced paresis and hematoma formation, suggesting that ATF3 limits these injury outcomes in wild-type mice. Next, we analyzed TBI-associated RAG and inflammatory gene expression in the cortical impact area. In contrast to the PNS, only some RAGs (Atf3, Timp1, and Sprr1a) were induced by TBI, and, surprisingly, some RAG encoding neuropeptides were downregulated. Notably, we identified ATF3 as TF-regulating proneuroinflammatory gene expression, including CCL and CXCL chemokines (Ccl2, Ccl3, Ccl4, and Cxcl1) and lipocalin. In Atf3 mutant mice, mRNA abundance was further enhanced upon TBI compared to wild-type mice, suggesting immune gene repression by wild-type ATF3. In accord, more immune cells were present in the lesion area of ATF3-deficient mice. Overall, we identified ATF3 as a new TF-mediating TBI-associated CNS inflammatory responses.


Asunto(s)
Factor de Transcripción Activador 3/inmunología , Lesiones Traumáticas del Encéfalo/inmunología , Lesiones Traumáticas del Encéfalo/patología , Inflamación/inmunología , Inflamación/patología , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes
10.
Mol Neurobiol ; 54(10): 8242-8262, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-27914009

RESUMEN

Stress experience modulates behavior, metabolism, and energy expenditure of organisms. One molecular hallmark of an acute stress response is a rapid induction of immediate early genes (IEGs) such as c-Fos and Egr family members. IEG transcription in neurons is mediated by the neuronal activity-driven gene regulator serum response factor (SRF). We show a first role of SRF in immediate and long-lasting acute restraint stress (AS) responses. For this, we employed a standardized mouse phenotyping protocol at the German Mouse Clinic (GMC) including behavioral, metabolic, and cardiologic tests as well as gene expression profiling to analyze the consequences of forebrain-specific SRF deletion in mice exposed to AS. Adult mice with an SRF deletion in glutamatergic neurons (Srf; CaMKIIa-CreERT2 ) showed hyperactivity, decreased anxiety, and impaired working memory. In response to restraint AS, instant stress reactivity including locomotor behavior and corticosterone induction was impaired in Srf mutant mice. Interestingly, even several weeks after previous AS exposure, SRF-deficient mice showed long-lasting AS-associated changes including altered locomotion, metabolism, energy expenditure, and cardiovascular changes. This suggests a requirement of SRF for mediating long-term stress coping mechanisms in wild-type mice. SRF ablation decreased AS-mediated IEG induction and activity of the actin severing protein cofilin. In summary, our data suggest an SRF function in immediate AS reactions and long-term post-stress-associated coping mechanisms.


Asunto(s)
Adaptación Psicológica/fisiología , Genes Inmediatos-Precoces/fisiología , Prosencéfalo/metabolismo , Factor de Respuesta Sérica/deficiencia , Estrés Psicológico/metabolismo , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Prosencéfalo/patología , Factor de Respuesta Sérica/genética , Estrés Psicológico/genética , Estrés Psicológico/patología , Factores de Tiempo
11.
Exp Neurol ; 279: 243-260, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26980486

RESUMEN

Fingolimod (FTY720) is a new generation oral treatment for multiple sclerosis (MS). So far, FTY720 was mainly considered to target trafficking of immune cells but not brain cells such as neurons. Herein, we analyzed FTY720's potential to directly alter neuronal function. In CNS neurons, we identified a FTY720 governed gene expression response. FTY720 upregulated immediate early genes (IEGs) encoding for neuronal activity associated transcription factors such as c-Fos, FosB, Egr1 and Egr2 and induced actin cytoskeleton associated genes (actin isoforms, tropomyosin, calponin). Stimulation of primary neurons with FTY720 enhanced neurite growth and altered growth cone morphology. In accordance, FTY720 enhanced axon regeneration in mice upon facial nerve axotomy. We identified components of a FTY720 engaged signaling cascade including S1P receptors, G12/13G-proteins, RhoA-GTPases and the transcription factors SRF/MRTF. In summary, we uncovered a broader cellular and therapeutic operation mode of FTY720, suggesting beneficial FTY720 effects also on CNS neurons during MS therapy and for treatment of other neurodegenerative diseases requiring neuroprotective and neurorestorative processes.


Asunto(s)
Axones/efectos de los fármacos , Clorhidrato de Fingolimod/farmacología , Expresión Génica/efectos de los fármacos , Inmunosupresores/farmacología , Esclerosis Múltiple/tratamiento farmacológico , Neuronas/metabolismo , Actinas/metabolismo , Animales , Axotomía , Células Cultivadas , Nervio Facial/efectos de los fármacos , Nervio Facial/crecimiento & desarrollo , Genes Inmediatos-Precoces/efectos de los fármacos , Conos de Crecimiento/efectos de los fármacos , Conos de Crecimiento/ultraestructura , Ratones , Ratones Endogámicos C57BL , Regeneración Nerviosa/efectos de los fármacos , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Neuritas/efectos de los fármacos , Neuronas/efectos de los fármacos , Factores de Transcripción/genética
12.
Int J Lang Commun Disord ; 51(3): 310-27, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26757345

RESUMEN

BACKGROUND: The prevalence of speech-language impairments in children have been estimated for several languages, primarily in developed countries. However, prevalence data is lacking for developing countries, such as Nepal. AIMS: (1) To obtain teacher estimates of incidence and overall prevalence of speech-language impairments and its subtypes as a function of gender, age and grade level; and (2) to validate the screening instrument on Nepalese children. METHODOLOGY: The adapted teachers' screening instrument, namely adapted Teachers' Speech and Language Referral Checklist (a-TSLRC), was administered in 2776 (690 and 2086) primary school children aged 5;00-11;11 years (mean = 8;11 years). The screening was conducted at four different points in time, i.e. Incidences I and II, and each incidence consisted of a testing and a retesting phase. Prior to this, teachers were trained in forum meetings, and an information sheet containing an overview of speech-language impairments, and guidelines/criteria for marking the occurrence of speech-language impairments in the TSLRC were disseminated. OUTCOMES & RESULTS: Overall prevalence of speech-language impairments in children was estimated as 8.11%. Specifically, overall speech problems were estimated as 4.68%, and language problems as 8.0%. Additionally, the prevalence by subtypes of speech-language impairments as categorized in the TSLRC were reported to be 2.95% for an articulation/phonological problems, 2.09% for stuttering, 3.42% for a voice problems, 4.97% for a receptive language problems and 7.74% for an expressive language problems. The internal consistency among items was sufficient and a good intra-rater reliability was obtained. CONCLUSIONS & IMPLICATIONS: The study indicates that the overall results of speech-language impairments in children via the adapted in-Nepalese criterion-referenced instrument are supported by international studies. In addition, justifiable reliability and validity was obtained. Therefore, based on these overall evidence, this instrument can be useful for the screening of speech-language impairments in primary school children in Nepal.


Asunto(s)
Lista de Verificación/estadística & datos numéricos , Países en Desarrollo , Trastornos del Desarrollo del Lenguaje/diagnóstico , Trastornos del Desarrollo del Lenguaje/epidemiología , Tamizaje Masivo , Servicios de Salud Escolar , Maestros , Trastornos del Habla/diagnóstico , Trastornos del Habla/epidemiología , Factores de Edad , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Nepal , Factores Sexuales
13.
Eur J Cell Biol ; 95(1): 42-56, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26589769

RESUMEN

The serum response factor (SRF) is a neuronal activity regulated transcription factor (TF) mediating an immediate early (IEGs, e.g. cFos, Egr1) and actin cytoskeletal gene response. SRF activity is adjusted by two competing cofactor families, ternary complex factors (TCF; e.g. Elk-1) and myocardin related transcription factors (MRTF). We investigated mechanisms of SRF activation upon seizure associated neuronal activity in mice. SRF serine 103 phosphorylation or promoter binding was not obviously changed upon neuronal activation. In contrast, a SRF directed proteomic analysis uncovered established and potentially novel components of SRF associated protein complexes whose abundance was modified by neuronal activity. This included the general transcription factor TFII-I for which we provide a first functional analysis in neurons. TFII-I modulated neuronal SRF target gene expression, enhanced nerve fiber growth and modulated the shape of neuronal growth cones. Interestingly, TFII-I modulated two SRF cofactors, Elk-1 and MRTF-A, in opposite directions. TFII-I and Elk-1 co-expression enhanced SRF target gene abundance, SRF promoter binding and neurite growth, whereas TFII-I and MRTF-A resulted in opposite outcomes. In summary, we provide a first proteome wide analysis of SRF associated proteins. We characterized TFII-I as modulator of SRF activity by imposing differential impact on two SRF cofactors.


Asunto(s)
Neuronas/metabolismo , Factor de Respuesta Sérica/metabolismo , Factores de Transcripción TFII/metabolismo , Animales , Inmunoprecipitación de Cromatina , Cromatografía Liquida , Modelos Animales de Enfermedad , Ensayo de Cambio de Movilidad Electroforética , Femenino , Regulación de la Expresión Génica/fisiología , Conos de Crecimiento/metabolismo , Células HEK293 , Humanos , Immunoblotting , Inmunoprecipitación , Masculino , Ratones , Ratones Endogámicos C57BL , Proteómica , Reacción en Cadena en Tiempo Real de la Polimerasa , Convulsiones/metabolismo , Espectrometría de Masas en Tándem , Factores de Transcripción/metabolismo
15.
Glia ; 63(6): 958-76, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25639799

RESUMEN

In multiple sclerosis (MS), neurons in addition to inflammatory cells are now considered to mediate disease origin and progression. So far, molecular and cellular mechanisms of neuronal MS contributions are poorly understood. Herein we analyzed whether neuron-restricted signaling by the neuroprotective transcription factor serum response factor (SRF) modulates de- and remyelination in a rodent MS model. In the mouse cuprizone model, neuron- (Srf (flox/flox;CaMKCreERT2)) but not glia-specific (Srf (flox/flox;PlpCreERT2)) SRF depletion impaired demyelination suggesting impaired debris clearance by astrocytes and microglia. This supports an important role of SRF expression in neurons but not oligodendrocytes in de- and remyelination. During remyelination, NG2- and OLIG2-positive cells of the oligodendrocyte lineage as well as de novo mRNA synthesis of myelin genes were also reduced in neuron-specific Srf mutants. Using the stripe assay, we demonstrate that cortices of cuprizone-fed wild-type mice elicited astrocyte and microglia activation whereas this was abrogated in cuprizone-fed neuron-specific Srf mutants. We identified CCL chemokines (e.g. CCL2) as neuron-derived SRF-regulated paracrine signals rescuing immune cell activation upon neuronal SRF deletion. In summary, we uncovered important roles of neurons and neuronally expressed SRF in MS associated de- and remyelination.


Asunto(s)
Esclerosis Múltiple/fisiopatología , Vaina de Mielina/fisiología , Neuronas/metabolismo , Factor de Respuesta Sérica/metabolismo , Animales , Astrocitos/patología , Astrocitos/fisiología , Células Cultivadas , Quimiocina CCL2/metabolismo , Cuprizona , Modelos Animales de Enfermedad , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Microglía/patología , Microglía/fisiología , Esclerosis Múltiple/patología , Vaina de Mielina/metabolismo , Vaina de Mielina/patología , Neuronas/patología , Oligodendroglía/patología , Oligodendroglía/fisiología , ARN Mensajero/metabolismo , Factor de Respuesta Sérica/genética
16.
PLoS One ; 6(10): e26089, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22022520

RESUMEN

During brain development, growth cones respond to attractive and repulsive axon guidance cues. How growth cones integrate guidance instructions is poorly understood. Here, we demonstrate a link between BDNF (brain derived neurotrophic factor), promoting axonal branching and ephrin-A5, mediating axonal repulsion via Eph receptor tyrosine kinase activation. BDNF enhanced growth cone filopodial dynamics and neurite branching of primary neurons. We show that ephrin-A5 antagonized this BDNF-evoked neuronal motility. BDNF increased ERK phosphorylation (P-ERK) and nuclear ERK entry. Ephrin-A5 suppressed BDNF-induced ERK activity and might sequester P-ERK in the cytoplasm. Neurotrophins are well established stimulators of a neuronal immediate early gene (IEG) response. This is confirmed in this study by e.g. c-fos, Egr1 and Arc upregulation upon BDNF application. This BDNF-evoked IEG response required the transcription factor SRF (serum response factor). Notably, ephrin-A5 suppressed a BDNF-evoked neuronal IEG response, suggesting a role of Eph receptors in modulating gene expression. In opposite to IEGs, long-term ephrin-A5 application induced cytoskeletal gene expression of tropomyosin and actinin. To uncover specific Eph receptors mediating ephrin-As impact on neurotrophin signaling, EphA7 deficient mice were analyzed. In EphA7 deficient neurons alterations in growth cone morphology were observed. However, ephrin-A5 still counteracted neurotrophin signaling suggesting that EphA7 is not required for ephrin and BDNF crosstalk. In sum, our data suggest an interaction of ephrin-As and neurotrophin signaling pathways converging at ERK signaling and nuclear gene activity. As ephrins are involved in development and function of many organs, such modulation of receptor tyrosine kinase signaling and gene expression by Ephs might not be limited to the nervous system.


Asunto(s)
Movimiento Celular/efectos de los fármacos , Efrina-A5/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Factores de Crecimiento Nervioso/farmacología , Neuronas/citología , Neuronas/enzimología , Animales , Factor Neurotrófico Derivado del Encéfalo/farmacología , Comunicación Celular/efectos de los fármacos , Núcleo Celular/efectos de los fármacos , Núcleo Celular/enzimología , Activación Enzimática/efectos de los fármacos , Genes Inmediatos-Precoces/genética , Conos de Crecimiento/efectos de los fármacos , Ratones , Neuritas/efectos de los fármacos , Neuritas/enzimología , Neuronas/efectos de los fármacos , Fosforilación/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Receptores de la Familia Eph/metabolismo , Factor de Respuesta Sérica/farmacología , Transducción de Señal/efectos de los fármacos
17.
Microb Cell Fact ; 8: 3, 2009 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-19133115

RESUMEN

Class IIa bacteriocins from lactic acid bacteria are small, cationic proteins with antilisterial activity. Within this class, the pediocins are those bacteriocins that share a highly conserved hydrophilic and charged N-terminal part harboring the consensus sequence -YGNGV- and a more variable hydrophobic and/or amphiphilic C-terminal part. Several pediocins have been isolated and characterized. Despite the structural similarities, their molecular weight varies, as well as their spectrum of antimicrobial activity. They exhibit important technological properties, e.g. thermostability and retaining of activity at a wide pH range, which along with the bactericidal action against Gram-positive food spoilage and pathogenic bacteria, make them an important class of biopreservatives. Much new information regarding the pediocins has emerged during the last years. In this review, we summarize and discuss all the available information regarding the sources of pediocins, the characteristics of their biosynthesis and production in fermentation systems, the characteristics of the known pediocin molecules, and their antibacterial action. The advances made by genetic engineering in improving the features of pediocins are also discussed, as well as their perspectives for future applications.

18.
Bioresour Technol ; 99(14): 6646-50, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18215516

RESUMEN

A direct plate bioassay procedure was applied for rapid and quantifiable assessment of the influence of various nutritional parameters on pediocin production by Pediococcus acidilactici NRRL B5627. Solid-state cultivation of the microorganism was done on MRS-based media over 3-and 6-hours incubation periods. Nutritional parameters assessed included the carbon source (glucose, sucrose, fructose, galactose, glycerol), and various salts (NH(4)PO(4), CaCl(2), KH(2)PO(4), MnSO(4).H(2)O). Glucose was found to be the optimal carbon source while glycerol exhibited the most suppressive effect. Using glucose as the carbon source, addition of various salts, in amounts used in liquid media commonly applied in the cultivation of the pediococci, was assessed with respect to bacteriocin production on a per cell basis. Experimental data obtained showed that several nutritional parameters repress pediocin production by P. acidilactici, while the direct plate assay proved to be a good pilot assay prior to conducting more intensive kinetic analysis in liquid cultivation.


Asunto(s)
Bacteriocinas/biosíntesis , Pediococcus/metabolismo , Bioensayo , Medios de Cultivo , Cinética
19.
Bioresour Technol ; 99(13): 5384-90, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18093831

RESUMEN

Fermentation broths of Pediococcus acidilactici NRRL B5627 exhibited a certain antimicrobial activity due to a bacteriocin produced during early growth and until the stationary phase of growth was reached (at optimum of 60% dissolved oxygen saturation). Its size was determined by electrospray ionization mass spectrometric analysis as 3.660 kDa. N-terminal sequencing showed that the bacteriocin had 19 amino acid residues in the order KYYGXNGVXTXGKHSXVDX. The purified bacteriocin is similar to pediocins isolated by various Pediococci and therefore, it belongs to the class IIa of bacteriocins and is thus designated pediocin SA-1. Sensitivity of the purified pediocin to various storage temperatures and enzyme treatments was examined. Purified pediocin SA-1 is heat stable for up to 60 min at 121 degrees C. Pediocin SA-1 is inhibitory to several food-borne pathogens and food spoilage bacteria. It appears to be significantly more effective against Listeria spp. compared to pediocin PD-1 produced by P. damnosus. The mode of action of the purified bacteriocin appears to be bactericidal.


Asunto(s)
Bacteriocinas/aislamiento & purificación , Bacteriocinas/farmacología , Pediococcus/química , Secuencia de Aminoácidos , Bacterias/clasificación , Bacterias/efectos de los fármacos , Bacteriocinas/biosíntesis , Bacteriocinas/química , Reactores Biológicos , Estabilidad de Medicamentos , Glucosa/metabolismo , Cinética , Lactatos/metabolismo , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Pediococcus/crecimiento & desarrollo , Pediococcus/metabolismo , Péptido Hidrolasas/metabolismo , Termodinámica
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