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1.
Int J Pediatr Otorhinolaryngol ; 175: 111776, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37951020

RESUMEN

OBJECTIVES: In remote communities of northern Australia, First Nations children with hearing loss are disproportionately at risk of poor school readiness and performance compared to their peers with no hearing loss. The aim of this trial is to prevent early childhood persisting otitis media (OM), associated hearing loss and developmental delay. To achieve this, we designed a mixed pneumococcal conjugate vaccine (PCV) schedule that could maximise immunogenicity and thereby prevent bacterial otitis media (OM) and a trajectory of educational and social disadvantage. METHODS: In two sequential parallel, open-label, randomised controlled trials, eligible infants were first allocated 1:1:1 to standard or mixed PCV primary schedules at age 28-38 days, then at age 12 months to a booster dose (1:1) of 13-valent PCV, PCV13 (Prevenar13®, +P), or 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugated vaccine, PHiD-CV10 (Synflorix®, +S). Here we report findings of standardised ear assessments conducted six-monthly from age 12-36 months, by booster dose. RESULTS: From March 2013 to September 2018, 261 children were allocated to booster + P (n = 131) or + S (n = 130). There were no significant differences in prevalence of any OM diagnosis by booster dose or when stratified by primary schedule. We found high, almost identical prevalence of OM in both boost groups at each age (for example 88% of 129 and 91% of 128 children seen, respectively, at primary endpoint age 18 months, difference -3% [95% Confidence Interval -11, 5]). At each age prevalence of bilateral OM was 52%-78%, and tympanic membrane perforation was 10%-18%. CONCLUSION: Despite optimal pneumococcal immunisation, the high prevalence of OM persists throughout early childhood. Novel approaches to OM prevention are needed, along with improved early identification strategies and evaluation of expanded valency PCVs.


Asunto(s)
Sordera , Otitis Media , Infecciones Neumocócicas , Lactante , Niño , Humanos , Preescolar , Recién Nacido , Australia/epidemiología , Vacunas Conjugadas/uso terapéutico , Otitis Media/epidemiología , Otitis Media/prevención & control , Otitis Media/tratamiento farmacológico , Vacunas Neumococicas , Streptococcus pneumoniae , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/prevención & control , Infecciones Neumocócicas/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto
2.
Environ Pollut ; 333: 122037, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37348699

RESUMEN

Honey bees (Apis mellifera L.) are one of the most important managed pollinators of agricultural crops. While potential effects of agricultural pesticides on honey bee health have been investigated in some settings, risks to honey bees associated with exposures occurring in the plant nursery setting have received little attention. We sought to identify and quantify pesticide levels present in honey bee-collected pollen harvested in two ornamental plant nurseries (i.e., Nursery A and Nursery B) in Connecticut. From June to September 2018, pollen was collected weekly from 8 colonies using bottom-mounted pollen traps. Fifty-five unique pesticides (including related metabolites) were detected: 24 insecticides, 20 fungicides, and 11 herbicides. Some of the pesticide contaminants detected in the pollen had not been applied by the nurseries, indicating that the honey bee colonies did not exclusively forage on pollen at their respective nursery. The average number of pesticides per sample was similar at both nurseries (i.e., 12.9 at Nursery A and 14.2 at Nursery B). To estimate the potential risk posed to honey bees from these samples, we utilized the USEPA's BeeREX tool to calculate risk quotients (RQs) for each pesticide within each sample. The median aggregate RQ for nurse bees was 0.003 at both nurseries, well below the acute risk level of concern (LOC) of ≥0.4. We also calculated RQs for larvae due to their increased sensitivity to certain pesticides. In total, 6 samples had larval RQs above the LOC (0.45-2.51), resulting from the organophosphate insecticide diazinon. Since 2015, the frequency and amount of diazinon detected in pollen increased at one of our study locations, potentially due to pressure to reduce the use of neonicotinoid insecticides. Overall, these data highlight the importance of considering all life stages when estimating potential risk to honey bee colonies from pesticide exposure.


Asunto(s)
Insecticidas , Residuos de Plaguicidas , Plaguicidas , Abejas , Animales , Residuos de Plaguicidas/análisis , Insecticidas/toxicidad , Insecticidas/análisis , Jardines , Diazinón/análisis , Connecticut , Plaguicidas/toxicidad , Plaguicidas/análisis , Polen/química , Medición de Riesgo
3.
Vaccine ; 40(7): 1054-1060, 2022 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-34996643

RESUMEN

BACKGROUND: Pneumococcal disease outbreaks of vaccine preventable serotype 4 sequence type (ST)801 in shipyards have been reported in several countries. We aimed to use genomics to establish any international links between them. METHODS: Sequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating. RESULTS: Outbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0-2 SNPs) with the common ancestor dated around 2017. CONCLUSION: The total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination.


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Brotes de Enfermedades , Finlandia , Genoma Bacteriano , Humanos , Irlanda del Norte , Noruega , Exposición Profesional , Filogenia , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/prevención & control , Polimorfismo de Nucleótido Simple , Serogrupo , Serotipificación , Navíos
4.
Environ Entomol ; 49(1): 203-210, 2020 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-31858127

RESUMEN

Reliance on the honey bee as a surrogate organism for risk assessment performed on other bees is widely challenged due to differences in phenology, life history, and sensitivity to pesticides between bee species. Consequently, there is a need to develop validated methods for assessing toxicity in non-Apis bees including bumble bees. The usefulness of small-scale, queenless colonies, termed microcolonies, has not been fully investigated for hazard assessment. Using the insect growth regulator diflubenzuron as a reference toxicant, we monitored microcolony development from egg laying to drone emergence using the Eastern bumble bee Bombus impatiens (C.), a non-Apis species native to North America. Microcolonies were monitored following dietary exposure to diflubenzuron (nominal concentrations: 0.1, 1, 10, 100, and 1,000 µg/liter). Microcolony syrup and pollen consumption was significantly reduced by diflubenzuron exposure. Pupal cell production was also significantly decreased at the highest diflubenzuron concentration assessed. Ultimately, diflubenzuron inhibited drone production in a concentration-dependent manner and a 42-d 50% inhibitory concentration (IC50) was determined. None of the dietary concentrations of diflubenzuron tested affected adult worker survival, or average drone weight. These data strengthen the foundation for use of this methodology, and provide valuable information for B. impatiens; however, more work is required to better understand the utility of the bumble bee microcolony model for pesticide hazard assessment.


Asunto(s)
Diflubenzurón , Himenópteros , Plaguicidas , Animales , Abejas , América del Norte , Polen
5.
Access Microbiol ; 1(10): e000065, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32974499

RESUMEN

Honey is a natural product with many beneficial properties including antimicrobial action. Production of hydrogen peroxide (H2O2) in diluted honey is central to this action. Here, we describe an optimized method for measuring levels of H2O2 in honey. This method is based on established methods, with the level of dilution, the time between dilution and reading the assay, and aeration of the samples during the assay identified as critical points for ensuring reliability and reproducibility. The method is cost-effective and easy to perform using common laboratory equipment. Using this method, we quantified the hydrogen peroxide content of five different, unprocessed polyfloral honeys collected in NC, USA. Our results show that H2O2 production by these honeys varies greatly, with some samples producing negligible levels of H2O2. We assessed the effect of colour on the assay by measuring the recovery of spiked H2O2 from light and dark honey and from serially diluted dark corn syrup, and found the amount of H2O2 that could be detected was lower in dark corn syrup and darker honey samples.

6.
Toxicol In Vitro ; 53: 20-28, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30048737

RESUMEN

Current regulatory immunotoxicity studies require the use of animal models. However, evolving regulatory requirements, the need to evaluate large numbers of chemicals efficiently and societal pressures are driving the development and utilization of alternative in vitro methods for identifying potential immunotoxicants. In line with these efforts, we developed a novel in vitro cell-based assay to evaluate effects on antigen presentation - a key step in successful immunization. In this assay, Ch27 B cells acquire and present hen egg lysozyme peptides to antigen-restricted 3A9 T cells, causing them to produce and secrete IL-2. IL-2 levels in the culture medium may be monitored to identify effects of immunotoxicant exposure on antigen uptake, processing or presentation by the Ch27 cells and on antigen recognition and IL-2 production and secretion by the 3A9 cells. IL-2 production was reduced in response to treatment with well-known immunotoxicants cyclosporin A (CYA), dexamethasone (DEX), azathioprine (AZPR), methotrexate (MOT) and benzo(a)pyrene (BAP) but was not affected by treatment with cyclophosphamide (CYPH). A negative control compound mannitol (MANN) altered neither cell viability nor IL-2 levels whereas the lysosomotrophic compound ammonium chloride (AMCL) reduced IL-2 production. This novel in vitro assay of immune function may be suitable for integration into a tiered testing battery for screening and prioritization of potential immunosuppressants.


Asunto(s)
Presentación de Antígeno , Linfocitos B/efectos de los fármacos , Factores Inmunológicos/farmacología , Linfocitos T/efectos de los fármacos , Animales , Linfocitos B/inmunología , Línea Celular , Técnicas de Cocultivo , Interleucina-2/inmunología , Ratones , Linfocitos T/inmunología
7.
Clin Exp Immunol ; 187(3): 408-417, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27859014

RESUMEN

In areas where Streptococcus pneumoniae is highly endemic, infants experience very early pneumococcal colonization of the upper respiratory tract, with carriage often persisting into adulthood. We aimed to explore whether newborns in high-risk areas have pre-existing pneumococcal-specific cellular immune responses that may affect early pneumococcal acquisition. Cord blood mononuclear cells (CBMC) of 84 Papua New Guinean (PNG; high endemic) and 33 Australian (AUS; low endemic) newborns were stimulated in vitro with detoxified pneumolysin (dPly) or pneumococcal surface protein A (PspA; families 1 and 2) and compared for cytokine responses. Within the PNG cohort, associations between CBMC dPly and PspA-induced responses and pneumococcal colonization within the first month of life were studied. Significantly higher PspA-specific interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-5, IL-6, IL-10 and IL-13 responses, and lower dPly-IL-6 responses were produced in CBMC cultures of PNG compared to AUS newborns. Higher CBMC PspA-IL-5 and PspA-IL-13 responses correlated with a higher proportion of cord CD4 T cells, and higher dPly-IL-6 responses with a higher frequency of cord antigen-presenting cells. In the PNG cohort, higher PspA-specific IL-5 and IL-6 CBMC responses were associated independently and significantly with increased risk of earlier pneumococcal colonization, while a significant protective effect was found for higher PspA-IL-10 CBMC responses. Pneumococcus-specific cellular immune responses differ between children born in pneumococcal high versus low endemic settings, which may contribute to the higher risk of infants in high endemic settings for early pneumococcal colonization, and hence disease.


Asunto(s)
Sangre Fetal/inmunología , Sangre Fetal/microbiología , Inmunidad Celular/inmunología , Infecciones Neumocócicas/inmunología , Streptococcus pneumoniae/inmunología , Anticuerpos Antibacterianos/inmunología , Células Presentadoras de Antígenos/inmunología , Antígenos Bacterianos/inmunología , Australia , Proteínas Bacterianas/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/microbiología , Células Cultivadas , Citocinas/inmunología , Femenino , Humanos , Recién Nacido , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/microbiología , Papúa Nueva Guinea , Infecciones Neumocócicas/microbiología , Embarazo , Riesgo
8.
Anaesthesia ; 71(10): 1144-52, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27501155

RESUMEN

Concerns have been raised about the effects on cognition of anaesthesia for surgery, especially in elderly people. We recorded cognitive decline in a cohort of 394 people (198 women) with median (IQR) age at recruitment of 72.6 (66.6-77.8) years, of whom 109 had moderate or major surgery during a median (IQR) follow-up of 4.1 (2.0-7.6) years. Cognitive decline was more rapid in people who on recruitment were: older, p = 0.0003; male, p = 0.027; had worse cognition, p < 0.0001; or carried the ε4 allele of apoliprotein E (APOEε4), p = 0.008; and after an operation if cognitive impairment was already diagnosed, p = 0.0001. Cognitive decline appears to accelerate after surgery in elderly patients diagnosed with cognitive impairment, but not other elderly patients.


Asunto(s)
Envejecimiento/psicología , Anestesia/efectos adversos , Disfunción Cognitiva/epidemiología , Evaluación Geriátrica/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Factores de Edad , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Memoria , Pruebas Neuropsicológicas/estadística & datos numéricos , Factores de Riesgo , Factores Sexuales
9.
Neuroimage ; 125: 643-656, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26285079

RESUMEN

The momentary, global functional state of the brain is reflected by its electric field configuration. Cluster analytical approaches consistently extracted four head-surface brain electric field configurations that optimally explain the variance of their changes across time in spontaneous EEG recordings. These four configurations are referred to as EEG microstate classes A, B, C, and D and have been associated with verbal/phonological, visual, subjective interoceptive-autonomic processing, and attention reorientation, respectively. The present study tested these associations via an intra-individual and inter-individual analysis approach. The intra-individual approach tested the effect of task-induced increased modality-specific processing on EEG microstate parameters. The inter-individual approach tested the effect of personal modality-specific parameters on EEG microstate parameters. We obtained multichannel EEG from 61 healthy, right-handed, male students during four eyes-closed conditions: object-visualization, spatial-visualization, verbalization (6 runs each), and resting (7 runs). After each run, we assessed participants' degrees of object-visual, spatial-visual, and verbal thinking using subjective reports. Before and after the recording, we assessed modality-specific cognitive abilities and styles using nine cognitive tests and two questionnaires. The EEG of all participants, conditions, and runs was clustered into four classes of EEG microstates (A, B, C, and D). RMANOVAs, ANOVAs and post-hoc paired t-tests compared microstate parameters between conditions. TANOVAs compared microstate class topographies between conditions. Differences were localized using eLORETA. Pearson correlations assessed interrelationships between personal modality-specific parameters and EEG microstate parameters during no-task resting. As hypothesized, verbal as opposed to visual conditions consistently affected the duration, occurrence, and coverage of microstate classes A and B. Contrary to associations suggested by previous reports, parameters were increased for class A during visualization, and class B during verbalization. In line with previous reports, microstate D parameters were increased during no-task resting compared to the three internal, goal-directed tasks. Topographic differences between conditions included particular sub-regions of components of the metabolic default mode network. Modality-specific personal parameters did not consistently correlate with microstate parameters except verbal cognitive style which correlated negatively with microstate class A duration and positively with class C occurrence. This is the first study that aimed to induce EEG microstate class parameter changes based on their hypothesized functional significance. Beyond the associations of microstate classes A and B with visual and verbal processing, respectively, our results suggest that a finely-tuned interplay between all four EEG microstate classes is necessary for the continuous formation of visual and verbal thoughts. Our results point to the possibility that the EEG microstate classes may represent the head-surface measured activity of intra-cortical sources primarily exhibiting inhibitory functions. However, additional studies are needed to verify and elaborate on this hypothesis.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/fisiología , Electroencefalografía , Pensamiento/fisiología , Humanos , Masculino , Procesamiento de Señales Asistido por Computador , Adulto Joven
10.
Inhal Toxicol ; 27(10): 468-80, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26309092

RESUMEN

Occupational exposure to halogenated platinum salts can trigger the development of asthma. The risk to the general population that may result from the use of platinum in catalytic converters and its emerging use as a diesel fuel additive is unclear. To investigate pulmonary responses to platinum, we developed a mouse model of platinum hypersensitivity. Mice were sensitized through application of ammonium hexachloroplatinate (AHCP) to the shaved back on days 0, 5 and 19, and to each ear on days 10, 11 and 12. On days 24 and 29, mice were challenged by oropharyngeal aspiration with AHCP in saline. Before and immediately after challenge, pulmonary responses were assessed using whole body plethysmography (WBP). A dose-dependent increase in immediate responses was observed in AHCP-sensitized and challenged mice. On days 26 and 31, changes in ventilatory responses to methacholine (Mch) aerosol were assessed by WBP; dose-dependent increases in Mch responsiveness occurred in sensitized mice. Lymph node cell counts indicate a proliferative response in lymph nodes draining the sites of application. Bronchoalveolar lavage fluid harvested from sensitized mice contained an average of 5% eosinophils compared to less than 0.5% in non-sensitized mice (p < 0.05); significant increases in total serum immunoglobulin E were observed for all sensitized mice. Although a second airway challenge on day 29 affected some results, only one airway challenge was needed to observe changes in lung function.


Asunto(s)
Alérgenos/toxicidad , Cloruros/toxicidad , Hipersensibilidad/etiología , Pulmón/efectos de los fármacos , Compuestos de Platino/toxicidad , Animales , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Recuento de Células , Modelos Animales de Enfermedad , Femenino , Hipersensibilidad/sangre , Hipersensibilidad/inmunología , Hipersensibilidad/fisiopatología , Inmunoglobulina E/sangre , L-Lactato Deshidrogenasa/metabolismo , Pulmón/inmunología , Pulmón/fisiopatología , Ratones Endogámicos BALB C
11.
Oecologia ; 179(1): 75-88, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25953117

RESUMEN

Ungulates often adjust their diet when food availability varies over time. However, it is poorly understood when and to what extent individuals change their diet and, if they do so, if all individuals of a population occupy distinct or similar dietary niches. In the arid Namibian Kunene Region, we studied temporal variations of individual niches in grazing gemsbok (Oryx gazella gazella) and predominantly browsing springbok (Antidorcas marsupialis). We used variation in stable C and N isotope ratios of tail hair increments as proxies to estimate individual isotopic dietary niches and their temporal plasticity. Isotopic dietary niches of populations of the two species were mutually exclusive, but similar in breadth. Isotopic niche breadth of gemsbok was better explained by within-individual variation than by between-individual variation of stable isotope ratios, indicating that gemsbok individuals were facultative specialists in using isotopically distinct local food resources. In contrast, inter- and intra-individual variations contributed similarly to the isotopic niche breadth of the springbok population, suggesting a higher degree of individual isotopic segregation in a more generalist ungulate. In both species, between-individual variation was neither explained by changes in plant primary productivity, sex, geographical position nor by group size. Within species, individual dietary niches overlapped partially, suggesting that both populations included individuals with distinct isotopic dietary niches. Our study provides the first evidence for isotopic dietary niche segregation in individuals of two distinct desert ungulates. Similar, yet isotopically distinct dietary niches of individuals may facilitate partitioning of food resources and thus individual survival in desert ecosystems.


Asunto(s)
Antílopes/crecimiento & desarrollo , Clima Desértico , Dieta , Ecosistema , Herbivoria/fisiología , Animales , Antílopes/fisiología , Isótopos de Carbono/análisis , Cabello/química , Humanos , Namibia , Isótopos de Nitrógeno/análisis , Especificidad de la Especie
12.
J Appl Toxicol ; 35(1): 29-40, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24532485

RESUMEN

The murine local lymph node assay (LLNA) is widely used to identify chemicals that may cause allergic contact dermatitis. Exposure to a dermal sensitizer results in proliferation of local lymph node T cells, which has traditionally been measured by in vivo incorporation of [(3) H]methyl thymidine. A more recent non-isotopic variation of the assay utilizes bromodeoxyuridine (BrdU) incorporation in vivo. To further improve the utility of this assay, we developed an ex vivo BrdU labeling procedure eliminating the need for in vivo injections. The results of this assay correctly identified a strong sensitizer (i.e., trimellitic anhydride) as well as weak/moderate sensitizers (i.e., eugenol, cinnamaldehyde and hexylcinnaminic aldehyde). As anticipated, neither non-sensitizers isopropanol and lactic acid nor the false negative chemical nickel II sulfate hexahydrate induced a positive threshold response in the assay. The results of this assay are in close agreement with those of the in vivo LLNA:BrdU-enzyme-linked immunosorbent assay labeling procedure. We also used the ex vivo BrdU LLNA procedure to evaluate ammonium hexachloroplatinate, ammonium tetrachloroplatinate and cis-diamminedichloroplatinum(II) and the assay correctly identified them as sensitizers based on the calculation of EC2 values. We conclude that this ex vivo BrdU labeling method offers predictive capacity comparable to previously established LLNA protocols while eliminating animal injections and the use of radioisotope. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.


Asunto(s)
Alérgenos/toxicidad , Bromodesoxiuridina , Dermatitis Alérgica por Contacto/etiología , Ensayo del Nódulo Linfático Local , Ganglios Linfáticos/efectos de los fármacos , Animales , Bromodesoxiuridina/metabolismo , Proliferación Celular/efectos de los fármacos , Dermatitis Alérgica por Contacto/inmunología , Determinación de Punto Final , Ensayo de Inmunoadsorción Enzimática , Femenino , Ganglios Linfáticos/inmunología , Recuento de Linfocitos , Ratones Endogámicos BALB C , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Pruebas de Toxicidad
13.
Lett Appl Microbiol ; 59(4): 422-31, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24935714

RESUMEN

Slow off-rate modified aptamer (SOMAmer) reagents were generated to several Staphylococcus aureus cell surface-associated proteins via SELEX with multiple modified DNA libraries using purified recombinant or native proteins. High-affinity binding agents with sub-nanomolar Kd 's were obtained for staphylococcal protein A (SpA), clumping factors (ClfA, ClfB), fibronectin-binding proteins (FnbA, FnbB) and iron-regulated surface determinants (Isd). Further screening revealed several SOMAmers that specifically bound to Staph. aureus cells from all strains that were tested, but not to other staphylococci or other bacteria. SpA and ClfA SOMAmers proved useful for the selective capture and enrichment of Staph. aureus cells, as shown by culture and PCR, leading to improved limits of detection and efficient removal of PCR inhibitors. Detection of Staph. aureus cells was enhanced by several orders of magnitude when the bacterial cell surface was coated with SOMAmers followed by qPCR of the SOMAmers. Furthermore, fluorescence-labelled SpA SOMAmers demonstrated their utility as direct detection agents in flow cytometry. Significance and impact of the study: Monitoring for microbial contamination of food, water, nonsterile products or the environment is typically based on culture, PCR or antibodies. Aptamers that bind with high specificity and affinity to well-conserved cell surface epitopes represent a promising novel type of reagents to detect bacterial cells without the need for culture or cell lysis, including for the capture and enrichment of bacteria present at low cell densities and for the direct detection via qPCR or fluorescent staining.


Asunto(s)
Aptámeros de Péptidos/metabolismo , Proteínas Bacterianas/metabolismo , Membrana Celular/metabolismo , Staphylococcus aureus/metabolismo , Afinidad de Anticuerpos , Aptámeros de Péptidos/química , Proteínas Bacterianas/química , Membrana Celular/química , Regulación Bacteriana de la Expresión Génica , Unión Proteica , Sensibilidad y Especificidad , Staphylococcus aureus/genética
14.
J Clin Microbiol ; 52(5): 1352-7, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24501028

RESUMEN

Nontypeable Haemophilus influenzae (NTHI) strains are responsible for respiratory-related infections which cause a significant burden of disease in Australian children. We previously identified a disparity in NTHI culture-defined carriage rates between Aboriginal and non-Aboriginal children (42% versus 11%). The aim of this study was to use molecular techniques to accurately determine the true NTHI carriage rates (excluding other culture-identical Haemophilus spp.) and assess whether the NTHI strain diversity correlates with the disparity in NTHI carriage rates. NTHI isolates were cultured from 595 nasopharyngeal aspirates collected longitudinally from asymptomatic Aboriginal (n=81) and non-Aboriginal (n=76) children aged 0 to 2 years living in the Kalgoorlie-Boulder region, Western Australia. NTHI-specific 16S rRNA gene PCR and PCR ribotyping were conducted on these isolates. Confirmation of NTHI by 16S rRNA gene PCR corrected the NTHI carriage rates from 42% to 36% in Aboriginal children and from 11% to 9% in non-Aboriginal children. A total of 75 different NTHI ribotypes were identified, with 51% unique to Aboriginal children and 13% unique to non-Aboriginal children (P<0.0001). The strain richness (proportion of different NTHI ribotypes) was similar for Aboriginal (19%, 65/346) and non-Aboriginal children (19%, 37/192) (P=0.909). Persistent carriage of the same ribotype was rare in the two groups, but colonization with multiple NTHI strains was more common in Aboriginal children than in non-Aboriginal children. True NTHI carriage was less than that estimated by culture. The Aboriginal children were more likely to carry unique and multiple NTHI strains, which may contribute to the chronicity of NTHI colonization and subsequent disease.


Asunto(s)
Infecciones por Haemophilus/virología , Haemophilus influenzae/genética , Preescolar , Humanos , Lactante , Recién Nacido , Nasofaringe/virología , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , Infecciones del Sistema Respiratorio/virología , Australia Occidental
15.
IEEE Trans Vis Comput Graph ; 18(12): 2178-87, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26357125

RESUMEN

Cerebral aneurysms are a pathological vessel dilatation that bear a high risk of rupture. For the understanding and evaluation of the risk of rupture, the analysis of hemodynamic information plays an important role. Besides quantitative hemodynamic information, also qualitative flow characteristics, e.g., the inflow jet and impingement zone are correlated with the risk of rupture. However, the assessment of these two characteristics is currently based on an interactive visual investigation of the flow field, obtained by computational fluid dynamics (CFD) or blood flow measurements. We present an automatic and robust detection as well as an expressive visualization of these characteristics. The detection can be used to support a comparison, e.g., of simulation results reflecting different treatment options. Our approach utilizes local streamline properties to formalize the inflow jet and impingement zone. We extract a characteristic seeding curve on the ostium, on which an inflow jet boundary contour is constructed. Based on this boundary contour we identify the impingement zone. Furthermore, we present several visualization techniques to depict both characteristics expressively. Thereby, we consider accuracy and robustness of the extracted characteristics, minimal visual clutter and occlusions. An evaluation with six domain experts confirms that our approach detects both hemodynamic characteristics reasonably.


Asunto(s)
Hemodinámica/fisiología , Aneurisma Intracraneal/patología , Aneurisma Intracraneal/fisiopatología , Modelos Cardiovasculares , Circulación Cerebrovascular/fisiología , Simulación por Computador , Humanos , Imagenología Tridimensional
16.
Lett Appl Microbiol ; 50(6): 633-8, 2010 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-20438617

RESUMEN

AIM: Contamination by Mollicutes is a significant challenge for research laboratories and biopharmaceutical industry. It leads to alteration of results or production quality as well as loss of time, materials and revenue. These organisms can czoriginate from mammalian, avian, insect, plant or fish cells. Culture-based methods may require 28 days to detect Mollicutes. Traditional microbiology could advantageously be replaced by nucleic acid testing for earlier detection. METHODS AND RESULTS: A membrane filtration-based concentration of the Mollicutes has been coupled to real-time transcription-mediated amplification (real-time TMA) to demonstrate these advantages. The eight species required by European Pharmacopoeia have been tested and were detected with sensitivity below 100 CFU per 20-ml sample. Co-culture experiments, in which Mollicutes are grown with CHO-S (suspension) or HEK 293 (adherent) cells, were also performed to respectively mimic a bioreactor or flask contamination. Despite the fact that Mollicutes can attach to or invade mammalian cells, they were consistently detected over multiple days. CONCLUSIONS: the sample preparation and amplification method used in this study increases sensitivity and reduces time-to-result for detection of Mollicutes. SIGNIFICANCE AND IMPACT OF THE STUDY: the described system allows real-time monitoring for microbial contamination of cell-based processes and products for the biopharmaceutical industry.


Asunto(s)
Reactores Biológicos/microbiología , Reacción en Cadena de la Polimerasa/métodos , Tenericutes/aislamiento & purificación , Animales , Células CHO , Línea Celular , Células/microbiología , Cricetinae , Cricetulus , Humanos , Tenericutes/genética , Transcripción Genética
17.
Vet Microbiol ; 145(3-4): 339-46, 2010 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-20400245

RESUMEN

The aim of this study was to determine whether Mycobacterium avium subspecies paratuberculosis (M. a. paratuberculosis) infection was present in macropods grazing with infected sheep on Kangaroo Island in 2001-2002, and to assess the likely role of such infection in the epidemiology of ovine paratuberculosis. Ileum and associated lymphatics from 482 macropods were examined using radiometric culture followed by PCR for IS900 and restriction endonuclease analysis (REA) for species identification, and isolates were strain typed using PCR for IS1311 and REA. Ileum and mesenteric lymph nodes from animals with positive tissue cultures or gross lesions suggestive of paratuberculosis were examined histologically. Faeces from a total of 840 animals were cultured in pools of 20, and individual faecal cultures were done from tissue culture positive animals, from those with microscopic lesions, and from selected animals with gross lesions. Eight animals (1.7%) yielded positive tissue cultures, and all isolates were the sheep (S) strain. Two animals that were tissue culture positive also had histopathological evidence of paratuberculosis. Twelve culture negative animals had microscopic lesions consistent with mycobacterial infection, and M. genavense was identified by PCR from a paraffin block from one of these animals. All faecal cultures were negative. These results indicate that a small proportion of macropods can become infected with M. a. paratuberculosis when grazing with infected sheep. However, excretion of large numbers of viable organisms is rare in macropods, and it is unlikely that macropods provide a wildlife reservoir of infection that would seriously compromise control efforts for paratuberculosis in sheep.


Asunto(s)
Macropodidae/microbiología , Mycobacterium avium subsp. paratuberculosis/aislamiento & purificación , Paratuberculosis/microbiología , Animales , Elementos Transponibles de ADN/genética , ADN Bacteriano/química , ADN Bacteriano/genética , Histocitoquímica/veterinaria , Mycobacterium avium subsp. paratuberculosis/genética , Paratuberculosis/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Australia del Sur/epidemiología
18.
Mutat Res ; 683(1-2): 57-67, 2010 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-19879883

RESUMEN

We performed experiments to characterize the inducibility of nucleotide excision repair (NER) in Caenorhabditis elegans, and to examine global gene expression in NER-deficient and -proficient strains as well as germline vs. somatic tissues, with and without genotoxic stress. We also carried out experiments to elucidate the importance of NER in the adult life of C. elegans under genotoxin-stressed and control conditions. Adult lifespan was not detectably different between wild-type and NER-deficient xpa-1 nematodes under control conditions. However, exposure to 6J/m(2)/day of ultraviolet C radiation (UVC) decreased lifespan in xpa-1 nematodes more than a dose of 100 J/m(2)/day in wild-type. Similar differential sensitivities were observed for adult size and feeding. Remarkably, global gene expression was nearly identical in young adult wild-type and xpa-1 nematodes, both in control conditions and 3h after exposure to 50 J/m(2) UVC. Neither NER genes nor repair activity were detectably inducible in young adults that lacked germ cells and developing embryos (glp-1 strain). However, expression levels of dozens of NER and other DNA damage response genes were much (5-30-fold) lower in adults lacking germ cells and developing embryos, suggesting that somatic and post-mitotic cells have a much lower DNA repair ability. Finally, we describe a refinement of our DNA damage assay that allows damage measurement in single nematodes.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Enzimas Reparadoras del ADN/genética , Reparación del ADN/genética , Regulación de la Expresión Génica/fisiología , Péptido 1 Similar al Glucagón/genética , Proteína de la Xerodermia Pigmentosa del Grupo A/genética , Animales , Biomarcadores/metabolismo , Caenorhabditis elegans/efectos de la radiación , Proteínas de Caenorhabditis elegans/genética , Reparación del ADN/efectos de la radiación , Enzimas Reparadoras del ADN/metabolismo , Perfilación de la Expresión Génica , Células Germinativas , Péptido 1 Similar al Glucagón/metabolismo , Calor , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Reproducción/efectos de la radiación , Tasa de Supervivencia , Rayos Ultravioleta , Proteína de la Xerodermia Pigmentosa del Grupo A/metabolismo
19.
P N G Med J ; 53(3-4): 191-206, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-23163191

RESUMEN

Infants in Papua New Guinea (PNG) are at a high risk of invasive pneumococcal disease, and a substantial burden of this falls on children less than six months old. PNG is planning to introduce a pneumococcal conjugate vaccine for infants in the near future, but to make the maximum impact neonatal immunization will have to be considered. To provide evidence on safety and immunogenicity for neonatal and early infant immunization, we undertook an open randomized controlled trial of 7-valent pneumococcal conjugate vaccine (7vPCV). 318 children received 7vPCV at ages 0, 1 and 2 months or at 1, 2 and 3 months or not at all. All children received 23-valent pneumococcal polysaccharide vaccine at age 9 months. This was a large and complex trial: village reporters visited participants weekly during the first year and fortnightly for a further 6 months and nurses monitored self-reported morbidity and collected many thousands of biological samples. The study team was remarkably successful in achieving the study aims, with 18-month follow-up completed on 77% of enrolled children and over 80% of scheduled samples collected. While the results of the trial will be reported elsewhere, this paper discusses the design of the study and dissects out some of the main reasons for its successful completion. Strong community engagement was an essential factor in success and the principles of equitable partnership and service provision led to a strong research partnership. A two-stage consent process, comprising primary assent followed by later informed consent, led to a high drop-out before initial enrolment, but an outstanding retention of those enrolled in the study. We conclude that factors such as strong community participation, reciprocity and a good relationship between the study team and participants are just as important as the technical elements of laboratory testing and data handling in ensuring the success of a vaccine trial in PNG.


Asunto(s)
Programas de Inmunización/organización & administración , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/administración & dosificación , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Papúa Nueva Guinea/epidemiología , Infecciones Neumocócicas/epidemiología , Evaluación de Programas y Proyectos de Salud , Vacunas Conjugadas
20.
J Psychopharmacol ; 24(6): 891-6, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19282422

RESUMEN

Phospholipase C (PLC) is one signalling effector enzyme whose activity is directly modulated by opioids. Several physiological studies have implicated PLC-linked pathways in in-vivo pain regulation and opioid tolerance. Co-administration of PLC-beta(2/3) activity blocker M119 with morphine resulted in a dramatic increase in morphine-induced amnesic effect in mice, proving a role for beta subunit of PLC enzyme in these processes. Administration of morphine to mice at amnesic dose increased PLC-beta(3) activity, with respect to basal value, in the membrane-soluble material from anterior cortex and hippocampal formation in brain areas. PLC-beta(3) appears to be simultaneously implicated in both analgesic and amnesic effects induced by administration of morphine to mice suggesting a commonality in the molecular mechanisms of morphine-induced analgesia and memory impairment.


Asunto(s)
Reacción de Prevención/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Hipocampo/efectos de los fármacos , Recuerdo Mental/efectos de los fármacos , Morfina/farmacología , Fosfolipasa C beta/metabolismo , Análisis de Varianza , Animales , Reacción de Prevención/fisiología , Corteza Cerebral/metabolismo , Relación Dosis-Respuesta a Droga , Hipocampo/metabolismo , Masculino , Recuerdo Mental/fisiología , Ratones , Narcóticos/farmacología , Receptores Opioides mu/metabolismo
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