Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 134
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Ultrasound Obstet Gynecol ; 60(1): 109-117, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34826157

RESUMEN

OBJECTIVE: Although fetal autopsy is generally recommended to confirm or refute the antemortem diagnosis, parental acceptance of the procedure has fallen over time, mainly due to its invasiveness. Contrast-enhanced microfocus CT (micro-CT) and high-field magnetic resonance imaging (HF-MRI, ≥ 3 Tesla) have both been suggested as non-invasive alternatives to conventional fetal autopsy for fetuses < 20 weeks of gestation. The aim of this study was to compare these two modalities in postmortem whole-body fetal imaging. METHODS: In this study, the imaging process and quality of micro-CT and HF-MRI were compared using both qualitative and quantitative assessments. For the qualitative evaluation, fetal anatomy experts scored 56 HF-MRI and 56 micro-CT images of four human fetuses aged 13-18 gestational weeks on two components: overall image quality and the ability to recognize and assess 21 anatomical structures. For the quantitative evaluation, participants segmented manually three organs with increasing complexity to assess interobserver variability. In addition, the signal-to-noise and contrast-to-noise ratios of five major organs were determined. RESULTS: Both imaging techniques were able to reach submillimeter voxel size. The highest resolution of micro-CT was 22 µm (isotropic), while the highest resolution of HF-MRI was 137 µm (isotropic). The qualitative image assessment form was sent to 45 fetal anatomy experts, of whom 36 (80%) responded. It was observed that micro-CT scored higher on all components of the qualitative assessment compared with HF-MRI. In addition, the quantitative assessment showed that micro-CT had lower interobserver variability and higher signal-to-noise and contrast-to-noise ratios. CONCLUSIONS: Our findings show that micro-CT outperforms HF-MRI in postmortem whole-body fetal imaging in terms of both quantitative and qualitative outcomes. Combined, these findings suggest that the ability to extract diagnostic information is greater when assessing micro-CT compared with HF-MRI images. We, therefore, believe that micro-CT is the preferred imaging modality as an alternative to conventional fetal autopsy for early gestation and is an indispensable tool in postmortem imaging services. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Feto , Imagen por Resonancia Magnética , Autopsia/métodos , Femenino , Feto/diagnóstico por imagen , Feto/patología , Edad Gestacional , Humanos , Imagen por Resonancia Magnética/métodos , Embarazo , Microtomografía por Rayos X/métodos
2.
Mol Psychiatry ; 23(2): 444-458, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28070119

RESUMEN

Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disease affecting about 2% of the general population. It is characterized by persistent intrusive thoughts and repetitive ritualized behaviors. While gene variations, malfunction of cortico-striato-thalamo-cortical (CSTC) circuits, and dysregulated synaptic transmission have been implicated in the pathogenesis of OCD, the underlying mechanisms remain largely unknown. Here we show that OCD-like behavior in mice is caused by deficiency of SPRED2, a protein expressed in various brain regions and a potent inhibitor of Ras/ERK-MAPK signaling. Excessive self-grooming, reflecting OCD-like behavior in rodents, resulted in facial skin lesions in SPRED2 knockout (KO) mice. This was alleviated by treatment with the selective serotonin reuptake inhibitor fluoxetine. In addition to the previously suggested involvement of cortico-striatal circuits, electrophysiological measurements revealed altered transmission at thalamo-amygdala synapses and morphological differences in lateral amygdala neurons of SPRED2 KO mice. Changes in synaptic function were accompanied by dysregulated expression of various pre- and postsynaptic proteins in the amygdala. This was a result of altered gene transcription and triggered upstream by upregulated tropomyosin receptor kinase B (TrkB)/ERK-MAPK signaling in the amygdala of SPRED2 KO mice. Pathway overactivation was mediated by increased activity of TrkB, Ras, and ERK as a specific result of SPRED2 deficiency and not elicited by elevated brain-derived neurotrophic factor levels. Using the MEK inhibitor selumetinib, we suppressed TrkB/ERK-MAPK pathway activity in vivo and reduced OCD-like grooming in SPRED2 KO mice. Altogether, this study identifies SPRED2 as a promising new regulator, TrkB/ERK-MAPK signaling as a novel mediating mechanism, and thalamo-amygdala synapses as critical circuitry involved in the pathogenesis of OCD.


Asunto(s)
Trastorno Obsesivo Compulsivo/metabolismo , Trastorno Obsesivo Compulsivo/patología , Proteínas Represoras/fisiología , Amígdala del Cerebelo/metabolismo , Animales , Conducta Compulsiva/metabolismo , Cuerpo Estriado/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/fisiología , Fluoxetina/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Ratones , Ratones Noqueados , Neuronas/metabolismo , Conducta Obsesiva/fisiopatología , Receptor trkB/fisiología , Proteínas Represoras/genética , Transducción de Señal , Sinapsis/metabolismo , Transmisión Sináptica/fisiología , Tálamo/metabolismo
3.
Eur J Clin Microbiol Infect Dis ; 37(11): 2181-2190, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30151777

RESUMEN

Detection of Salmonella Paratyphi A stool carriers by conventional stool culture media is hindered by the absence of hydrogen sulphide production compared to most other Salmonella serovars. This study evaluated the detection of Salmonella Paratyphi A in stool samples using Salmonella chromogenic media compared to a conventional medium. Four chromogenic media, COMPASS Salmonella agar (Biokar Diagnostics, Beauvais, France), BBL™ CHROMagar™ Salmonella (BD Diagnostics, Erembodegem-Aalst, Belgium), Brilliance™ Salmonella agar (Oxoid Ltd., Basingstoke, UK) and Salmonella PLUS CHROMagar™ (CHROMagar, Paris, France), were compared to conventional Salmonella-Shigella agar (Oxoid Ltd.). The colony morphology of 29 freshly grown stock isolates (Salmonella and competing organisms) was assessed. The limit of detection (LOD) was also determined using saline and stool suspensions. Finally, recognizability of Salmonella Paratyphi A isolates was assessed using 20 human stool samples spiked with different concentrations of Salmonella Paratyphi A. All Salmonella Paratyphi A isolates demonstrated detectable growth with typical purple-coloured colonies that could be clearly differentiated from competing organisms on all four chromogenic media. The LOD for Salmonella Paratyphi A was 103 colony-forming units (CFU)/ml for all media, except for Brilliance agar (105 CFU/ml of stool). Salmonella Paratyphi A was easy to differentiate from competing organisms in the spiked stool samples. Colony yields improved when an enrichment step (Selenite-F broth (BD Diagnostics, Erembodegem-Aalst, Belgium)) and prolonged incubation for 48 h were performed. Chromogenic media demonstrated good specificity and a low LOD for the detection of Salmonella Paratyphi A in stool samples.


Asunto(s)
Heces/microbiología , Fiebre Paratifoidea/diagnóstico , Fiebre Paratifoidea/microbiología , Salmonella paratyphi A/fisiología , Técnicas Bacteriológicas , Humanos , Límite de Detección , Reproducibilidad de los Resultados , Serogrupo
4.
Eur J Clin Microbiol Infect Dis ; 36(11): 2101-2107, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28623550

RESUMEN

Campylobacter infection is a common cause of diarrhea among international travelers. We studied antibiotic resistance patterns among Campylobacter isolates obtained from international travelers according to travel destination. Three collections of isolates obtained from international travelers between 2007 and 2014 (Institute of Tropical Medicine, the "Laboratoire Hospitalier Universitaire de Bruxelles "and the Belgian National Reference Centre for Campylobacter) were used. Isolates were tested for minimal inhibitory concentration (MIC) values (E-test macromethod) for fluoroquinolones, macrolides, tetracyclines, amoxicillin-clavulanic acid, and meropenem. Single isolates from 261 travelers were available; median (IQR) age was 25.4 (4-42) years, 85.8% were symptomatic (information for 224 patients available). Overall resistance to ciprofloxacin was 60.9%, ranging from 50.8% in Africa to 75.0% in Asia. Resistance to erythromycin was 4.6%, with the highest rate observed for Southern Asia (15.2%, seven isolates, six of them recovered from patients returning from India). A total of 126 isolates (48.3%) were resistant to tetracycline. No resistance to amoxicillin-clavulanic acid or meropenem was detected. Ciprofloxacin resistance tended to increase over time (53.9% in 2007 versus 72.2% in 2014), erythromycin resistance remained stable (median annual resistance 4.2%). Most (86.2%) ciprofloxacin-resistant isolates had MIC values ≥32 mg/l, and all erythromycin-resistant isolates had MIC values ≥256 mg/l. Co-resistance to ciprofloxacin and erythromycin was observed in 11 (4.2%) isolates, seven of which came from Southern Asia. Among all regions of travel, more than half of Campylobacter isolates were resistant to ciprofloxacin. Overall resistance to erythromycin was below 5% but reached 15.2% in Southern Asia.


Asunto(s)
Antibacterianos/farmacología , Infecciones por Campylobacter/microbiología , Campylobacter/efectos de los fármacos , Campylobacter/aislamiento & purificación , Enfermedades Transmisibles Importadas/microbiología , Adolescente , Adulto , Combinación Amoxicilina-Clavulanato de Potasio/farmacología , Campylobacter/clasificación , Infecciones por Campylobacter/tratamiento farmacológico , Niño , Preescolar , Ciprofloxacina/farmacología , Enfermedades Transmisibles Importadas/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple , Eritromicina/farmacología , Femenino , Humanos , Masculino , Meropenem , Pruebas de Sensibilidad Microbiana , Tienamicinas/farmacología , Adulto Joven
5.
Clin Orthop Relat Res ; 475(12): 2963-2969, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28808951

RESUMEN

BACKGROUND: Clinical weightbearing provocation tests, like the duck walk test, may be of value in diagnosing or screening for medial meniscal tears. However, evidence of the diagnostic accuracy of the duck walk test is lacking. QUESTIONS/PURPOSES: (1) To determine the sensitivity and specificity of the duck walk test in diagnosing medial meniscal tears. (2) To determine whether tear location, tear cause (traumatic versus degenerative), and ACL insufficiency were associated with differences in the sensitivity and specificity of the test. METHODS: A convenience sample of 136 patients of all ages was retrospectively analyzed by evaluating the outpatient knee clinic appointment list of one orthopaedic surgeon for patients with a broad range of knee injuries who had a prior MRI before (24%) or after (76%) physical examination and had a duck walk test stated in their patient records. Of 230 patients with MRI requested by one orthopaedic surgeon attributable to knee complaints, 136 (59%) fulfilled the inclusion criteria; 70 (52%) patients were male and 66 (49%) were female, with a mean age of 42 (± SD 14) years. The duck walk test was performed in case of suspected meniscal injury, based on mechanism of injury, general joint line pain, and/or mechanical complaints (ie, locking, giving away). The test is performed by squatting and "waddling" before rising and is positive in case of general joint line pain or painful "clicking". Interobserver repeatability was not evaluated, but the test is well defined and leaves little room for difference in interpretation. Diagnostic accuracy measures were evaluated. Since the convenience sample in this study consisted of patients who had a duck walk test and MRI, and a positive result of the duck walk test almost certainly increased the probability that MRI would be ordered in the majority (76%) of the patients, the test properties calculated here-especially sensitivity-should be considered inflated. RESULTS: The calculated sensitivity of the duck walk test was 71% (95% CI, 59%-81%) and there was low specificity of 39% (95% CI, 27%-52%). We found no difference in sensitivity between medial (67%; 95% CI, 51%-80%) and lateral (76%; 95% CI, 50%-92%; p = 0.492) meniscal tears. With the numbers available, we compared these patients with patients without a history of trauma and with an intact ACL. We found no difference among patients with traumatic tears (79%; 95% CI, 59%-91%; p = 0.253) and in patients with ACL tears (77%; 95% CI, 46%-94%; p = 0.742). CONCLUSIONS: Because of the issue of verification bias, the actual sensitivity of this test in practice is likely much lower than the calculated sensitivity we observed. In addition, the test did not seem to perform better in patients with trauma or ACL insufficiency, nor was it more effective in detecting medial than lateral tears, although the numbers on some of those comparisons were rather small. Based on these results, we conclude that used alone, the duck walk test likely has little value in practice as a screening test. However, it is conceivable that it could be used in combination with other provocative tests for screening purposes. Future studies might consider using it as a means to best identify which patients should undergo MRI for the possibility of a meniscal tear. LEVEL OF EVIDENCE: Level III, diagnostic study.


Asunto(s)
Marcha , Meniscos Tibiales/fisiopatología , Examen Físico/métodos , Lesiones de Menisco Tibial/diagnóstico , Caminata , Adulto , Lesiones del Ligamento Cruzado Anterior/diagnóstico , Lesiones del Ligamento Cruzado Anterior/fisiopatología , Fenómenos Biomecánicos , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Meniscos Tibiales/diagnóstico por imagen , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Lesiones de Menisco Tibial/diagnóstico por imagen , Lesiones de Menisco Tibial/etiología , Lesiones de Menisco Tibial/fisiopatología , Soporte de Peso
6.
J Dairy Sci ; 95(4): 1603-16, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22459808

RESUMEN

Selective precipitation is a common method for the isolation of ß-casein, using the different calcium sensitivities of the individual caseins and the selective solubility of ß-casein at a low temperature. In previous studies, it has been indicated that the ß-casein yield depends on the physicochemical characteristics of the casein raw material used for fractionation. The objective of this study was to evaluate and compare the solubility of α(S)- and ß-casein in solutions of micellar casein, sodium caseinate, and calcium caseinate as a function of pH and temperature. Additionally, the solubility of isolated α(S)- and ß-casein fractions in demineralized water, ultrafiltration permeate, and a calcium-depleted milk salt solution was investigated depending on the pH and temperature. Furthermore, micellar casein, sodium caseinate, and calcium caseinate were subjected to a calcium chloride-precipitation process to determine the solubility of α(S)- and ß-casein in calcium chloride precipitate, which is produced during selective precipitation, as a function of temperature and pH. Generally, the temperature had only a marginal influence on the α(S)-casein solubility compared with the ß-casein solubility, whereas the solubility was shown to be strongly influenced by the pH. Our results suggest that the yield of ß-casein obtained during isolation by means of selective precipitation may be a result of the solubility characteristics of α(S)- and ß-casein in calcium chloride precipitate. Manufacturers may consider a simple solubility experiment before the ß-casein isolation process by means of selective precipitation to predict ß-casein yield.


Asunto(s)
Caseínas/química , Caseínas/aislamiento & purificación , Animales , Calcio , Precipitación Química , Concentración de Iones de Hidrógeno , Luz , Micelas , Leche/química , Dispersión de Radiación , Solubilidad , Soluciones , Temperatura , Agua
7.
Histochem Cell Biol ; 136(1): 103-15, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21681518

RESUMEN

The specific function of the epithelium as critical barrier between the intestinal lumen and the organism's internal microenvironment is reflected by permanent maintenance of intercellular junctions and cellular polarity. The intestinal epithelial cells are responsible for absorption of nutritional components, facing mechanical stress and a changing oxygen supplementation via blood stream. Oxygen itself can regulate the barrier and the absorptive function of the epithelium. Therefore, we compared the dish cell culture, the transwell-like membrane culture and the oxygen enriched air-liquid interface (ALI) culture. We demonstrated strong influence of the different culture conditions on morphology and function of intestinal porcine epithelial cell lines in vitro. ALI culture resulted in a significant increase in cell number, epithelial cell layer thickness and expression as well as apical localisation of the microvilli-associated protein villin. Remarkable similarities regarding the morphological parameters were observed between ALI cultures and intestinal epithelial cells in vivo. Furthermore, the functional analysis of protein uptake and degradation by the epithelial cells demonstrated the necessity of sufficient oxygen supply as achieved in ALI cultures. Our study is the first report providing marked evidence that optimised oxygen supply using ALI cultures directly affects the morphological differentiation and functional properties of intestinal epithelial cells in vitro.


Asunto(s)
Diferenciación Celular , Células Epiteliales/citología , Mucosa Intestinal/citología , Citoesqueleto de Actina/metabolismo , Aire , Animales , Células Cultivadas , Células Epiteliales/metabolismo , Microscopía Electrónica de Transmisión de Rastreo , Microvellosidades/metabolismo , Oxígeno , Porcinos
8.
J Wound Care ; 20(6): 280-4, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21727877

RESUMEN

OBJECTIVE: To evaluate the clinical benefits, primarily tolerability and reduction in pain levels, associated with the use of a PHMB-impregnated biosynthetic cellulose dressing (Suprasorb X + PHMB) on paediatric heel lacerations. METHOD: These lacerations were caused when children, who were being transported on their parents' bicycles, got their heels trapped in the wheel spokes. Where these injuries just comprised skin contusion and laceration, treatment had previously comprised cleansing followed by application of conventional dressings and moist wound healing dressings. However, the high incidence of infection necessitated regular dressing changes, which caused parents and children stress and anxiety. This clinical evaluation assessed the benefits of a new treatment protocol, where the PHMB-impregnated biocellulose dressing was applied and left in situ until epithelialisation occurred. A cork splint was used for 3 days to prevent pes equinus and to let the ankle joint rest. Change in wound size (cm²), incidence of local infection, wound bed characteristics and pain levels (measured on a 0-10 paediatric pain scale) were assessed at 3-day intervals during the 14-day treatment period. Satisfaction with the dressing was also evaluated. RESULTS: Twenty children (mean age 5.6 years (± 1.33) were recruited into the study and included in the analysis. The mean baseline wound area was 8.60cm² (± 6.57). The mean time to complete wound closure was 12.95 days (± 7.69) with a mean total of 4.70 visits (± 1.56). The mean VAS pain score was 9.55 (± 0.69), compared with 0.15 (± 0.37) on day 14 (p<0.003). At the second visit (after 3 days) 17 of the 20 children were reported to be free of pain. No cases of local infection were noted. CONCLUSION: The dressing was found to be child and parent friendly. The evaluation also showed that it was well tolerated and achieved good healing outcome. It has now been incorporated into the clinic's treatment protocol for these wounds. CONFLICT OF INTEREST: None. The authors have no relevant financial interest in this article. All authors were involved in the critical revision of the manuscript for important intellectual content.


Asunto(s)
Vendajes , Ciclismo/lesiones , Biguanidas/uso terapéutico , Materiales Biocompatibles , Celulosa , Desinfectantes/uso terapéutico , Traumatismos de los Pies/terapia , Talón , Laceraciones/terapia , Niño , Preescolar , Femenino , Humanos , Masculino , Países Bajos , Cicatrización de Heridas
9.
Nat Commun ; 12(1): 4692, 2021 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-34344881

RESUMEN

The plasma-induced charge of non-spherical microparticles is a crucial parameter in complex plasma physics, aerosol science and astrophysics. Yet, the literature describes this charge by two competing models, neither of which has been experimentally verified or refuted. Here we offer experimental proof that the charge on a two-particle cluster (doublet) in the spatial afterglow of a low-pressure plasma equals the charge that would be obtained by the smallest enclosing sphere and that it should therefore not be based on its geometrical capacitance but rather on the capacitance of its smallest enclosing sphere. To support this conclusion, the size, mass and charge of single particles (singlets) and doublets are measured with high precision. The measured ratio between the plasma-afterglow-induced charges on doublets and singlets is compared to both models and shows perfect agreement with the predicted ratio using the capacitance of the smallest enclosing sphere, while being significantly dissimilar to the predicted ratio based on the particle's geometrical capacitance.

10.
Clin Microbiol Infect ; 27(4): 590-596, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32505586

RESUMEN

OBJECTIVES: Areas with declining malaria transmission in sub-Saharan Africa have recently witnessed important changes in the aetiology of childhood acute febrile illness (AFI). We describe the aetiology of AFI in a high malaria transmission area in rural Burkina Faso. METHODS: In a prospective hospital-based diagnostic study, children aged 3 months to 15 years with AFI were recruited and assessed using a systematic diagnostic protocol, including blood cultures, whole blood PCR on a selection of bacterial pathogens, malaria diagnostics and a multiplex PCR on nasopharyngeal swabs targeting 21 viral and 4 bacterial respiratory pathogens. RESULTS: A total of 589 children with AFI were enrolled from whom an infectious disease was considered in 575 cases. Acute respiratory tract infections, malaria and invasive bacterial infections (IBI) accounted for 179 (31.1%), 175 (30.4%) and 75 (13%) of AFI cases respectively; 16 (21.3%) of IBI cases also had malarial parasitaemia. A viral pathogen was demonstrated from the nasopharynx in 157 children (90.7%) with respiratory tract symptoms. Of all children with viral respiratory tract infections, 154 (92.4% received antibiotics, whereas no antibiotic was provided in 13 (17%) of IBI cases. CONCLUSIONS: Viral respiratory infections are a common cause of childhood AFI in high malaria transmission areas, next to malaria and IBI. These findings highlight the importance of interventions to improve targeted treatment with antimicrobials. Most patients with viral infections received antibiotics unnecessarily, while a considerable number with IBI did not receive antibiotics.


Asunto(s)
Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/epidemiología , Malaria/epidemiología , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Adolescente , Burkina Faso/epidemiología , Niño , Preescolar , Femenino , Fiebre , Humanos , Lactante , Malaria/transmisión , Masculino , Infecciones del Sistema Respiratorio/epidemiología , Población Rural
11.
Ultrasound Obstet Gynecol ; 33(6): 665-9, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19479678

RESUMEN

OBJECTIVE: To evaluate the time required and failure rate for completion of nuchal translucency thickness (NT) measurements with increased maternal body mass index (BMI). METHODS: This was a retrospective review of ultrasound examinations for NT measurement in 11-14-week singleton pregnancies performed at a single site from 2004 to 2007. Women were stratified by prepregnancy BMI into normal weight (BMI, 18.5-24.9 kg/m(2)), overweight (BMI, 25.0-29.9 kg/m(2)) and obese Class I (BMI, 30.0-34.9 kg/m(2)), Class II (BMI, 35.0-39.9 kg/m(2)) and Class III (BMI >or= 40.0 kg/m(2)) groups. The failure rate, the time required for measurement, and the total study time in min were evaluated by BMI class for the first attempt and for all attempts at NT measurement. RESULTS: A total of 2508 women underwent attempted NT screening with complete data available on 1678 women (1707 examinations). The failure rate for NT screening varied significantly according to BMI (P < 0.001). At the first attempt, the median time for NT measurement varied significantly according to BMI (normal weight group, 9.7 (interquartile range (IQR) 4.4, 19.0) min; overweight group, 8.8 (4.0, 19.8) min; obese Class I, 9.6 (4.8, 20.4) min; Class II, 14.1 (5.0, 28.2) min; Class III, 12.3 (4.6, 22.7) min; P < 0.01), as did the total study time (normal group, 16.4 (10.1, 26.6) min; overweight group, 15.7 (9.8, 25.0) min, Class I, 17.3 (10.3, 29.2) min; Class II, 23.0 (12.2, 36.1) min; Class III, 18.7 (11.0, 30.8) min; P = 0.002). For all attempts also, the median time for NT measurement varied significantly according to BMI (normal weight group, 9.7 (IQR 4.4, 19.0) min; overweight group, 8.8 (4.0, 19.9) min; obese Class I, 9.6 (4.8, 21.0) min; Class II, 14.1 (5.0, 28.7) min; Class III, 12.3 (4.6, 22.5) min; P < 0.01), as did the total study time (normal weight group, 16.4 (10.2, 26.7) min; overweight group, 15.7 (9.8, 25.1) min; Class I, 17.6 (10.4, 29.9) min; Class II, 23.2 (12.0, 37.5) min; Class III, 18.7 (11.9, 31.9) min; P < 0.001). CONCLUSION: As maternal BMI increases, the time required to obtain NT measurements and the failure rate increase. Before the ultrasound examination, patients with a BMI over 30 should be counseled regarding the need for additional time and failure rates for first-trimester screening.


Asunto(s)
Medida de Translucencia Nucal/métodos , Obesidad/diagnóstico por imagen , Adulto , Índice de Masa Corporal , Femenino , Edad Gestacional , Humanos , Medida de Translucencia Nucal/normas , Sobrepeso/diagnóstico por imagen , Embarazo , Primer Trimestre del Embarazo , Valores de Referencia , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo
12.
Mar Genomics ; 37: 1-17, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28970064

RESUMEN

The biodiversity, ecosystem services and climate variability of the Antarctic continent and the Southern Ocean are major components of the whole Earth system. Antarctic ecosystems are driven more strongly by the physical environment than many other marine and terrestrial ecosystems. As a consequence, to understand ecological functioning, cross-disciplinary studies are especially important in Antarctic research. The conceptual study presented here is based on a workshop initiated by the Research Programme Antarctic Thresholds - Ecosystem Resilience and Adaptation of the Scientific Committee on Antarctic Research, which focussed on challenges in identifying and applying cross-disciplinary approaches in the Antarctic. Novel ideas and first steps in their implementation were clustered into eight themes. These ranged from scale problems, through risk maps, and organism/ecosystem responses to multiple environmental changes and evolutionary processes. Scaling models and data across different spatial and temporal scales were identified as an overarching challenge. Approaches to bridge gaps in Antarctic research programmes included multi-disciplinary monitoring, linking biomolecular findings and simulated physical environments, as well as integrative ecological modelling. The results of advanced cross-disciplinary approaches can contribute significantly to our knowledge of Antarctic and global ecosystem functioning, the consequences of climate change, and to global assessments that ultimately benefit humankind.


Asunto(s)
Organismos Acuáticos/fisiología , Ecosistema , Investigación Interdisciplinaria , Regiones Antárticas , Biodiversidad , Cambio Climático , Congresos como Asunto , Ecología , Genómica
13.
Med Hypotheses ; 68(3): 558-61, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17030097

RESUMEN

Over the past century, the incidence of cancer rose markedly in developed countries. Many underlying factors are known, but not all of them. Over the same century, advances in public health and hygiene practically eradicated many infectious illnesses, and exposure to some untargeted infectious agents has also declined. There are reasons to suspect that these two trends are linked. Although some viruses and one bacterium are known to be oncogenic, a high percentage of infectious agents, 71% of viruses tested in one study, have shown oncolytic properties. Some of these agents have minimal or no clinical consequences, and some are - or were - quite ubiquitous. Many types of cancer are unusually susceptible to several different agents, sometimes 10-1000 times more susceptible than normal cells. When wild-type or attenuated viruses are used to treat cancer, they are often more effective with smaller tumors, and it may be that nascent, undetectable cancers are especially vulnerable. Environmental exposure to bacteria and viruses may provide natural protection from cancer by attacking it at this stage, or inducing the body to do so. Immunity to an infectious agent can attenuate its oncolytic effect, but generally does not stop it, so both initial and repeated exposures may be protective. As more direct evidence, treatment of animals with selected live virus vaccines has provided protection from cancer, and in humans, exposure to two specific infectious agents is known to correlate with a reduced risk of cancer. The significant decline in exposure to infectious agents over the past century may have inadvertently weakened this naturally protective mechanism, driving cancer rates up. There is considerable research on the impact of oncogenic agents, but surprisingly little regarding the impact of oncolytic agents on cancer rates. An understanding of the relationship between natural infections and the suppression of cancer may lead to prophylactic measures against cancer, improved public health policies regarding vaccination programs and hygiene, and greater insight into cancer treatment as well.


Asunto(s)
Infecciones Bacterianas/prevención & control , Exposición a Riesgos Ambientales , Neoplasias/epidemiología , Neoplasias/microbiología , Virosis/prevención & control , Humanos , Incidencia , Neoplasias/prevención & control , Neoplasias/virología
14.
Biochim Biophys Acta ; 1290(3): 210-4, 1996 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-8765122

RESUMEN

The pmmA gene encoding a bifunctional phosphomannomutase/phosphoglucomutase (PMM/PGM) from the photosynthetic prokaryote, Prochlorothrix hollandica has been cloned and sequenced. The gene encodes a 51827 Da polypeptide 48% identical to the PMM of Azospirillum brasilense, 37% identical to the PGMs of pathogenic Neisseria sp. and 37% identical to the bifunctional AlgC PGM/PMM of Pseudomonas aeruginosa. The pmmA gene encodes an enzyme having both PGM and PMM activities as judged by both enzyme assays and complementation analysis in which the cloned gene partially corrected the pgm-1 mutation of Escherichia coli.


Asunto(s)
Proteínas Bacterianas/genética , Cianobacterias/genética , Genes Bacterianos , Fosfotransferasas (Fosfomutasas)/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Cianobacterias/enzimología , Datos de Secuencia Molecular , Células Procariotas/enzimología , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Especificidad por Sustrato
15.
Tob Control ; 14(2): 114-7, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15791021

RESUMEN

OBJECTIVE: To validate self reports of cigarette and smokeless tobacco (snus) use in a prospective cohort of adolescents. DESIGN: A cross sectional analysis of a cohort sub-sample. SETTING: County of Stockholm, Sweden. SUBJECTS: 520 adolescents in the final grade of junior high school (mean age 15.0 years). MAIN OUTCOME MEASURE: Concordance between self reported tobacco use and saliva cotinine concentration. RESULTS: Using a cut point of 5 ng/ml saliva cotinine to discriminate active tobacco use, there was a 98% concordance between self reported non-use in the past month and cotinine concentration. The sensitivity of the questionnaire compared to the saliva cotinine test, used as the gold standard, was 90% and the specificity 93%. One hundred and fifteen out of 520 subjects (22%) reported monthly tobacco use. Among these, 67% (46/69) of the exclusive cigarette smokers, 82% (23/28) of exclusive snus users, and 94% (15/16) of mixed users (cigarettes + snus) had cotinine concentrations above 5 ng/ml. Among subjects reporting daily use 96% (64/67) had saliva cotinine concentrations above the cut point. Exclusive current cigarette users were more likely to be classified discordantly by questionnaire and cotinine test compared to snus users (odds ratio 3.2, 95% confidence interval 1.2 to 8.6). CONCLUSION: This study confirms the reliability of adolescents' self reported tobacco use. In a context of low exposure to environmental tobacco smoke a cut off for saliva cotinine of 5 ng/ml reliably discriminated tobacco users from non-users. Irregular use of tobacco in this age group probably explains the discrepancy between self reported use and cotinine concentrations.


Asunto(s)
Conducta del Adolescente/psicología , Autoevaluación (Psicología) , Fumar/psicología , Tabaco sin Humo , Adolescente , Biomarcadores/análisis , Cotinina/análisis , Estudios Transversales , Femenino , Humanos , Masculino , Estudios Prospectivos , Reproducibilidad de los Resultados , Saliva/química , Fumar/epidemiología , Encuestas y Cuestionarios , Suecia/epidemiología
16.
J Perinatol ; 35(5): 328-31, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25474553

RESUMEN

OBJECTIVE: Early initiation of low-dose aspirin (LDA) may reduce preeclampsia risk. We sought to determine whether LDA was beneficial when initiated <17w0d, within a trial of high-risk women enrolled <26w0d. STUDY DESIGN: Secondary analysis of the Maternal-Fetal Medicine Units High-Risk Aspirin study, including women enrolled <17w0d, randomized to LDA (60 mg day(-1)) or placebo with chronic hypertension (CHTN, n=186), diabetes (n=191) or prior preeclampsia (n=146). The primary outcome was preeclampsia at any time in pregnancy, secondary outcomes were early preeclampsia (<34w0d), late preeclampsia (⩾34w), small for gestational age (SGA; neonatal birthweight <10th %) and composite (early preeclampsia or SGA). Outcomes were compared by exact Χ(2)-tests. RESULTS: Baseline characteristics were similar between treatment groups. Aspirin was associated with a lower rate of late-onset preeclampsia ⩾34w (17.36% vs 24.42%, P=0.047), with a 41% reduction in women with CHTN (18.28% vs 31.18%, P=0.041). There were no other significant differences in the outcome. CONCLUSION: Aspirin initiated <17w0d reduced the risk for late-onset preeclampsia by 29% supporting the practice of early initiation of aspirin in high-risk women.


Asunto(s)
Aspirina/administración & dosificación , Preeclampsia/prevención & control , Adulto , Peso al Nacer , Femenino , Edad Gestacional , Humanos , Recién Nacido , Embarazo , Resultado del Embarazo , Factores de Riesgo
17.
Mol Cell Biol ; 35(14): 2495-502, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25963656

RESUMEN

The small GTPase Rap1 controls the actin cytoskeleton by regulating Rho GTPase signaling. We recently established that the Rap1 effectors Radil and Rasip1, together with the Rho GTPase activating protein ArhGAP29, mediate Rap1-induced inhibition of Rho signaling in the processes of epithelial cell spreading and endothelial barrier function. Here, we show that Rap1 induces the independent translocations of Rasip1 and a Radil-ArhGAP29 complex to the plasma membrane. This results in the formation of a multimeric protein complex required for Rap1-induced inhibition of Rho signaling and increased endothelial barrier function. Together with the previously reported spatiotemporal control of the Rap guanine nucleotide exchange factor Epac1, these findings elucidate a signaling pathway for spatiotemporal control of Rho signaling that operates by successive protein translocations to and complex formation at the plasma membrane.


Asunto(s)
Proteínas Activadoras de GTPasa/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Transducción de Señal , Proteínas de Unión al GTP rap1/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Células Cultivadas , Proteínas Activadoras de GTPasa/genética , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HEK293 , Humanos , Uniones Intercelulares/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Microscopía Confocal , Unión Proteica , Transporte de Proteínas , Interferencia de ARN , Proteínas de Unión al GTP rap1/genética , Proteínas de Unión al GTP rho/genética
18.
AIDS ; 14(15): 2239-46, 2000 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-11089611

RESUMEN

OBJECTIVE: To characterize immune phenotype and function in hepatitis C virus (HCV) infection in the presence and absence of HIV-1 infection. DESIGN: Cross-sectional comparison among controls (group A), patients with HCV infection (group B), HCV-HIV-1 coinfected patients (group C), coinfected patients receiving treatment for HIV-1 (group D), and untreated HIV-1 infected patients (group E). METHODS: Flow cytometric analysis for lymphocyte phenotypes, lymphocyte proliferation and cytokine production by ELISPOT. RESULTS: HCV infected patients tended to have an increased percentage of activated (CD38, HLA-DR) CD8 cells (group A, 2+/-1.4%; group B, 6+/-3.9%; P=0.08). Proliferative responses to non-HCV antigens were comparable in group A and group B subjects. A greater proportion of group B patients had stimulation indices (SI) > 3 to the HCV protein NS3 compared to group C and D patients (67%, 0%, and 11% respectively; P < 0.003), but only two patients in group B had SI > or = 5. The SI to NS3 was significantly higher in group B patients [median, 4; interquartile range (IQR), 3-9) than in group C (median, 2; IQR, 1-3; P < 0.04) or group D (median, 1; IQR, 1-4; P < 0.009) patients. Plasma HCV RNA levels correlated directly with alanine aminotransferase levels (p, 0.52; P < 0.05) and inversely with the number of CD4 lymphocytes (rho, -0.55; P < 0.009) and proliferation to NS3 (p, -0.55; P < 0.009). CONCLUSIONS: Lymphocytes of HCV infected patients show weak proliferative responses to HCV antigens while responses to other antigens are preserved. Infection with HIV-1 potentiates this deficiency. Poor CD4 T cell responses to HCV are associated with and may determine the failure to control HCV propagation.


Asunto(s)
Infecciones por VIH/inmunología , VIH-1 , Antígenos de la Hepatitis/inmunología , Antígenos de la Hepatitis C/inmunología , Hepatitis C/inmunología , Adulto , Linfocitos T CD4-Positivos/inmunología , Femenino , Infecciones por VIH/complicaciones , Hepatitis C/complicaciones , Humanos , Activación de Linfocitos , Subgrupos Linfocitarios/inmunología , Masculino , Persona de Mediana Edad , Fenotipo
19.
Neuropsychopharmacology ; 23(2): 205-15, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10882847

RESUMEN

Repetitive transcranial magnetic stimulation (rTMS) is increasingly used as a therapeutic tool in various neurological and psychiatric disorders, and we recently found that it has a neuroprotective effect both in vitro and in vivo. However, the neurochemical mechanisms underlying the therapeutic effects are still unknown. We investigated the effects of long-term rTMS on the expression of brain-derived neurotrophic factor (BDNF), cholecystokinin (CCK), and neuropeptide tyrosine (NPY) mRNA in rat brain. In situ hybridization revealed a significant increase in BDNF mRNA in the hippocampal areas CA3 and CA3c, the granule cell layer, as well as in the parietal and the piriform cortex after rTMS. BDNF-like immunoreactivity was markedly increased in the same areas. A significant increase in CCK mRNA was observed in all brain regions examined. NPY mRNA expression, in contrast, was not altered. The present results suggest that BDNF may contribute to the neuroprotective effects of rTMS. Furthermore, the rTMS-induced changes in BDNF and CCK expression are similar to those reported after antidepressant drug treatment and electroconvulsive seizures, suggesting that a common molecular mechanism may underlie different antidepressant treatment strategies.


Asunto(s)
Encéfalo/metabolismo , Colecistoquinina/genética , Neuropéptido Y/genética , ARN Mensajero/biosíntesis , Estimulación Magnética Transcraneal/uso terapéutico , Animales , Factor Neurotrófico Derivado del Encéfalo/biosíntesis , Factor Neurotrófico Derivado del Encéfalo/genética , Corteza Cerebral/metabolismo , Colecistoquinina/biosíntesis , Giro Dentado/metabolismo , Estimulación Eléctrica/instrumentación , Hipocampo/metabolismo , Masculino , Neuropéptido Y/biosíntesis , Vías Olfatorias/metabolismo , Lóbulo Parietal/metabolismo , Ratas , Ratas Wistar , Tiempo
20.
Neuropsychopharmacology ; 24(4): 337-49, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11182529

RESUMEN

The neuroendocrine and behavioral effects of repetitive transcranial magnetic stimulation (rTMS) were investigated in two rat lines selectively bred for high and low anxiety-related behavior. The stimulation parameters were adjusted according to the results of accurate computer-assisted and magnetic resonance imaging-based reconstructions of the current density distributions induced by rTMS in the rat and human brain, ensuring comparable stimulation patterns in both cases. Adult male rats were treated in two 3-day series under halothane anesthesia. In the forced swim test, rTMS-treatment induced a more active coping strategy in the high anxiety-related behavior rats only (time spent struggling; 332% vs. controls), allowing these animals to reach the performance of low anxiety-related behavior rats. In contrast, rTMS-treated low anxiety-related behavior rats did not change their swimming behavior. The development of active coping strategies in high anxiety-related behavior rats was accompanied by a significantly attenuated stress-induced elevation of plasma corticotropin and corticosterone concentrations. In summary, the behavioral and neuroendocrine effects of rTMS of frontal brain regions in high anxiety-related behavior rats are comparable to the effects of antidepressant drug treatment. Interestingly, in the psychopathological animal model repetitive transcranial magnetic stimulation induced changes in stress coping abilities in the high-anxiety line only.


Asunto(s)
Ansiedad/terapia , Conducta Animal/efectos de la radiación , Depresión/terapia , Campos Electromagnéticos , Sistemas Neurosecretores/efectos de la radiación , Adaptación Psicológica/efectos de la radiación , Hormona Adrenocorticotrópica/sangre , Animales , Ansiedad/sangre , Ansiedad/complicaciones , Simulación por Computador , Corticosterona/sangre , Depresión/sangre , Depresión/complicaciones , Modelos Animales de Enfermedad , Estimulación Eléctrica/instrumentación , Lóbulo Frontal/efectos de la radiación , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipotálamo-Hipofisario/efectos de la radiación , Masculino , Aprendizaje por Laberinto/efectos de la radiación , Sistemas Neurosecretores/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , Sistema Hipófiso-Suprarrenal/efectos de la radiación , Ratas , Ratas Endogámicas , Ratas Wistar , Tiempo de Reacción/efectos de la radiación , Estrés Fisiológico , Factores de Tiempo , Estimulación Magnética Transcraneal
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA