Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Microbiol Spectr ; 10(5): e0245022, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36129286

RESUMO

The isolation of pure, single colonies lies at the heart of experimental microbiology. However, a microbial colony typically contains around 1 million cells at all stages of the life cycle. Here, we describe a novel cell chromatography method that facilitates the capture, purification, and interrogation of microbial cell populations from both single and mixed cultures. The method described relies on, but is not limited to, differences in surface charge to separate bacterial strains. The method is fully biocompatible, leading to no significant loss of cell viability. The chromatographic capture of cells, combined with selective elution methods, facilitates a greater level of experimental control over the sample inputs required for downstream high-throughput and high-sensitivity analytical methods. The application of the method for interrogating the antibiotic resistance of bacterial strains and for the separation of bacteria from environmental samples is illustrated. IMPORTANCE This is the first report of a method for separating microbial cells using chromatography, with full retention of cell viability. Differences in the surface chemistry of microbial cells provides a means of attracting cells to immobilized microbeads. Some cells are attracted, and some are repelled. The differences in, for example, surface charge can be harnessed to capture, interrogate, and separate environmental samples, thus circumventing the need to use conventional bacterial plating methods. This method will greatly facilitate drug discovery and bioprospecting for novel microbial compounds.


Assuntos
Bactérias , Cromatografia
5.
Eur J Cancer Care (Engl) ; 27(4): e12852, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29667288

RESUMO

Treatment of cancer-related symptoms represents a major challenge for physicians. The purpose of this pilot study was to determine whether a brief bedside visual art intervention (BVAI) facilitated by art educators improves mood, reduces pain and anxiety in patients with haematological malignancies. Thirty-one patients (21 women and 10 men) were invited to participate in a BVAI where the goal of the session was to teach art technique for ~30 min. Primary outcome measures included the change in visual analog scale, the State-Trait Anxiety Inventory and the Positive and Negative Affect Schedule scale, from baseline prior to and immediately post-BVAI. Total of 21 patients (19 women and two men) participated. A significant improvement in positive mood and pain scores (p = .003 and p = .017 respectively) as well as a decrease in negative mood and anxiety (p = .016 and p = .001 respectively) was observed. Patients perceived BVAI as overall positive (95%) and wished to participate in future art-based interventions (85%). This accessible experience, provided by artists within the community, may be considered as an adjunct to conventional treatments in patients with cancer-related mood symptoms and pain, and future studies with balanced gender participation may support the generalisability of these findings.


Assuntos
Afeto , Ansiedade/terapia , Arteterapia/métodos , Dor do Câncer/terapia , Neoplasias Hematológicas/terapia , Adulto , Idoso , Ansiedade/psicologia , Dor do Câncer/psicologia , Feminino , Neoplasias Hematológicas/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Projetos Piloto , Adulto Jovem
6.
Phys Rev Lett ; 120(9): 094801, 2018 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-29547316

RESUMO

Terahertz (THz) radiation promises breakthrough advances in compact advanced accelerators due to the gigavolts-per-meter fields achievable, but the challenge of maintaining overlap and synchronism between beams and short laser-generated THz pulses has so far limited interactions to the few-millimeter scale. We implement a novel scheme for simultaneous group and phase velocity matching of nearly single-cycle THz radiation with a relativistic electron beam for meter-scale inverse free-electron laser interaction in a magnetic undulator, resulting in energy modulations of up to 150 keV using modest THz pulse energies (≤1 µJ). Using this scheme, we demonstrate for the first time the use of a laser-based THz source for bunch-length compression and time-stamping of a relativistic electron beam.


Assuntos
Modelos Teóricos , Radiação Terahertz , Aceleradores de Partículas
7.
Oncogene ; 34(39): 5025-36, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-25531318

RESUMO

RNA-binding proteins (RBPs) bind to and post-transcriptionally regulate the stability of mRNAs. La-related protein 1 (LARP1) is a conserved RBP that interacts with poly-A-binding protein and is known to regulate 5'-terminal oligopyrimidine tract (TOP) mRNA translation. Here, we show that LARP1 is complexed to 3000 mRNAs enriched for cancer pathways. A prominent member of the LARP1 interactome is mTOR whose mRNA transcript is stabilized by LARP1. At a functional level, we show that LARP1 promotes cell migration, invasion, anchorage-independent growth and in vivo tumorigenesis. Furthermore, we show that LARP1 expression is elevated in epithelial cancers such as cervical and non-small cell lung cancers, where its expression correlates with disease progression and adverse prognosis, respectively. We therefore conclude that, through the post-transcriptional regulation of genes such as mTOR within cancer pathways, LARP1 contributes to cancer progression.


Assuntos
Autoantígenos/fisiologia , Neoplasias/patologia , Processamento Pós-Transcricional do RNA , Ribonucleoproteínas/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Progressão da Doença , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Metástase Neoplásica , RNA Mensageiro/genética , Antígeno SS-B
8.
Cytokine ; 64(1): 413-21, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23727325

RESUMO

INTRODUCTION: Ovarian Cancer is the leading cause of death from gynecological malignancy. The poor prognosis is mainly due to presentation at a late stage and poor response to therapy. Much research is needed to identify diagnostic and prognostic biomarkers as well as therapeutic targets for ovarian cancer. Interleukin-8 is expressed by many tumour types and is known to have mitogenic, motogenic and angiogenic effects on tumour cells. AIMS: The aim of this study was to investigate the expression of IL-8 and IL-8 receptors (IL-8RA and IL-8RB) in different histological subtypes of ovarian tumours, as potential prognostic biomarkers in ovarian tumours. MATERIALS AND METHODS: Immunohitochemistry was used to study the expression of IL-8 and IL-8 receptors in 115 ovarian tumours including 21 benign tumours, 25 borderline tumours and 69 carcinomas of serous, clear cell, endometrioid and mucinous types. The correlation of expression profile, tumour type, stage, and progression free survival and overall survival was statistically analysed. RESULTS: IL-8 and IL-8 receptors were expressed in all types of tumours with variable intensity and subcellular distribution. There was a statistically significant correlation between levels of expression and tumour stage and tumour type, being mostly significant in serous tumours. No correlation with patient progression free survival or overall survival was found. CONCLUSION: This is the first study investigating the expression of IL-8 and IL-8 receptors using immunohistochemistry in different types of ovarian tumours, including benign and borderline tumours. IL-8 and IL-8RA are potential prognostic biomarkers and therapeutic targets in ovarian cancer, particularly in ovarian serous carcinoma.


Assuntos
Interleucina-8/metabolismo , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Receptores de Interleucina-8/metabolismo , Adenocarcinoma de Células Claras/metabolismo , Adenocarcinoma Mucinoso/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Endometrioide/metabolismo , Carcinoma Epitelial do Ovário , Cistadenocarcinoma Seroso/metabolismo , Intervalo Livre de Doença , Feminino , Humanos , Interleucina-8/biossíntese , Estadiamento de Neoplasias , Prognóstico , Receptores de Interleucina-8/biossíntese , Sobrevida
9.
Placenta ; 34(7): 583-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23642640

RESUMO

INTRODUCTION: The purpose of this study was to define gross patterns of umbilical cord hypercoiling and determine correlations with histological features in the placenta and/or perinatal outcomes such as stillbirth. METHODS: Gross images of placentas with hypercoiled umbilical cords (>3 coils/10 cm) were assigned a major umbilical coiling pattern and the direction (right or left) of the coiling. Definitions of 4 gross coiling patterns were established: undulating, rope, segmented, and linked, each with progressively deeper indentations in cord diameter. Outcome variables obtained from placental pathology reports and maternal medical records included histological abnormalities indicative of significant chronic fetal vascular obstruction, such as fetal vascular thrombi, avascular villi, villous stromal-vascular karyorrhexis, and fetal thrombotic vasculopathy, and stillbirth. RESULTS: 318 placentas/umbilical cords met inclusion criteria. The rope pattern was the most common (52%), followed by the undulating (26%), segmented (19%) and linked (3%) patterns. The segmented and linked gross coiling patterns were significantly correlated with histologic evidence of chronic fetal vascular obstruction and stillbirth, when compared with the ropeand undulating patterns. Cords with right twists were also significantly correlated with histologic evidence of chronic fetal vascular obstruction and stillbirth when compared with cords with left twists. The number of cord coils per 10 cm did not correlate with any of the outcome variables. CONCLUSIONS: Among hypercoiled umbilical cords, specific gross patterns of coiling can be recognized, and patterns with the most significant indentation or pinching of the cord diameter are associated with histological evidence of chronic fetal vascular obstruction and stillbirth.


Assuntos
Doenças Fetais/patologia , Placenta/patologia , Natimorto , Cordão Umbilical/patologia , Adolescente , Adulto , Feminino , Idade Gestacional , Humanos , Pessoa de Meia-Idade , Gravidez , Cordão Umbilical/irrigação sanguínea
10.
Oncogene ; 32(38): 4586-92, 2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-23128397

RESUMO

In embryonic stem (ES) cells, bivalent chromatin domains containing H3K4me3 and H3K27me3 marks silence developmental genes, while keeping them poised for activation following differentiation. We have identified gene sets associated with H3K27me3 and H3K4me3 marks at transcription start sites in a high-grade ovarian serous tumour and examined their association with epigenetic silencing and malignant progression. This revealed novel silenced bivalent marked genes, not described previously for ES cells, which are significantly enriched for the PI3K (P<10(-7)) and TGF-ß signalling pathways (P<10(-5)). We matched histone marked gene sets to gene expression sets of eight normal fallopian tubes and 499 high-grade serous malignant ovarian samples. This revealed a significant decrease in gene expression for the H3K27me3 and bivalent gene sets in malignant tissue. We then correlated H3K27me3 and bivalent gene sets to gene expression data of ovarian tumour 'stem cell-like' sustaining cells versus non-sustaining cells. This showed a significantly lower expression for the H3K27me3 and bivalent gene sets in the tumour-sustaining cells. Similarly, comparison of matched chemo-sensitive and chemo-resistant ovarian cell lines showed a significantly lower expression of H3K27me3/bivalent marked genes in the chemo-resistant compared with the chemo-sensitive cell line. Our analysis supports the hypothesis that bivalent marks are associated with epigenetic silencing in ovarian cancer. However it also suggests that additional tumour specific bivalent marks, to those known in ES cells, are present in tumours and may potentially influence the subsequent development of drug resistance and tumour progression.


Assuntos
Cromatina/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Inativação Gênica , Histonas/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Antineoplásicos/farmacologia , Imunoprecipitação da Cromatina , Epigênese Genética , Epigenômica , Feminino , Regulação Neoplásica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Gradação de Tumores , Neoplasias Ovarianas/patologia
11.
Theriogenology ; 78(2): 308-14, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22538002

RESUMO

Currently, there is no method of accurately and non-invasively diagnosing pregnancy in polar bears. Specific proteins may exhibit altered profiles in the feces of pregnant bears, but predicting appropriate candidate proteins to investigate is speculative at best. The objective of this study was to identify potential pregnancy biomarker proteins based on their increased abundance in the feces of pregnant polar bears compared to pseudopregnant females (controls) using two-dimensional in-gel electrophoresis (2D-DIGE) and mass spectrometry (MS). Three 2D-DIGE gels were performed to evaluate fecal protein profiles from controls (n=3) and pregnant polar bears (n=3). There were 2224.67±52.39 (mean±SEM) spots resolved per gel. Of these, only five proteins were elevated in the pregnant group (P<0.05), and seven additional spots tended to be higher (0.0599.9% confidence interval. The 11 spots represented seven distinct proteins, five of which were significantly more abundant in the pregnant group: IgGFc-binding protein, filamin-C, carboxypeptidase B, transthyretin, and immunoglobulin heavy chain variable region. To our knowledge, this was the first study that employed 2D-DIGE to identify differentially expressed proteins in fecal samples to characterize a physiological condition other than those related to gastrointestinal disorders. These promising results provided a strong foundation for ensuing efforts to develop a non-invasive pregnancy assay for use in both captive and wild polar bears.


Assuntos
Animais de Zoológico , Fezes/química , Proteínas da Gravidez/análise , Ursidae/fisiologia , Animais , Biomarcadores , Eletroforese em Gel Bidimensional/métodos , Eletroforese em Gel Bidimensional/veterinária , Feminino , Espectrometria de Massas/métodos , Espectrometria de Massas/veterinária , Gravidez , Proteínas da Gravidez/metabolismo
12.
Reprod Domest Anim ; 47 Suppl 6: 222-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23279504

RESUMO

The objectives of this study were to assess the effects of season, breeding activity, age and latitude on fecal testosterone metabolite concentrations in captive, adult male polar bears (Ursus maritimus). Fourteen polar bears from 13 North American zoos were monitored for 12-36 months, producing 25-year-long testosterone profiles. Results indicated that testosterone was significantly higher during the breeding season (early January through the end of May) compared with the non-breeding season with the highest concentrations excreted from early January through late March. Variations in excretion patterns were observed among individuals and also between years within an individual, with testosterone peaks closely associated with breeding activity. Results indicate that fecal testosterone concentrations are influenced by season, breeding activity and age, but not by latitude. This is the first report describing longitudinal fecal testosterone metabolite concentrations in individual adult male polar bears.


Assuntos
Animais de Zoológico , Fezes/química , Testosterona/química , Ursidae/fisiologia , Animais , Masculino , Testosterona/metabolismo , Fatores de Tempo
13.
Anim Reprod Sci ; 116(3-4): 376-80, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19282115

RESUMO

Currently, there are few inexpensive, reliable, effective methods for commercially separating X- and Y-chromosome bearing fresh and frozen bovine sperm. The objective of these experiments was to determine the efficacy of a commercially available post-thaw bovine semen sexing kit, HeiferPlus (HP) which claims to alter the sex ratio in favor of female calves following artificial insemination. Three trials included the insemination of hyperstimulated cows with Control or HP-treated semen, non-surgical embryo collection on Day 7, and a combined PCR/dot blot assay to determine embryo sex. Chi-square analysis showed that the Control group produced a greater proportion (p<0.0005) of female embryos than the HP group. There were no differences in the proportions of transferable compared with degenerate embryos or in number of ovulations, embryos, and unfertilized ova collected from Control compared with HP groups. When treatments were combined, one of the two bulls used in the hyperstimulation studies produced an overall greater proportion of females (p<0.05), suggesting a bull effect. Another trial involved the insemination of cows synchronized via OvSynch((R)) with fetal sexing via ultrasonography. Results of these studies indicated that HP semen sexing kit did not alter the sex ratio in favor of females in either hyperstimulated or single-ovulating cows; however, potential bull effects may be further evaluated to understand the capacity of HP with semen from specific bulls. Additionally, perhaps the sex of the surviving embryo can be manipulated by the maternal side, through ovarian, hormonal, oviductal, or uterine influences.


Assuntos
Ovulação/fisiologia , Kit de Reagentes para Diagnóstico , Sêmen/citologia , Processos de Determinação Sexual , Superovulação/fisiologia , Animais , Bovinos , Comércio , Eficiência , Feminino , Congelamento , Inseminação Artificial/métodos , Masculino , Gravidez , Kit de Reagentes para Diagnóstico/veterinária , Sêmen/fisiologia , Pré-Seleção do Sexo/métodos , Razão de Masculinidade
16.
Phytopathology ; 94(8): 901-11, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18943112

RESUMO

ABSTRACT Fire blight of apple and pear is initiated by epiphytic populations of Erwinia amylovora on flower stigmas. Predicting this disease and managing it with microbial antagonists depends on an understanding of bacterial colonization on stigmas. Detached 'Manchurian' crab apple flowers were inoculated with E. amylovora and subjected to a range of constant temperatures or various fluctuating temperature regimes. Results may have application to disease risk assessment systems such as the Cougarblight model, which now are based on in vitro growth of the pathogen. In other experiments, detached crab apple flowers and attached 'Gala' apple flowers were maintained at different temperatures for various periods before inoculation with E. amylovora or antagonists (Pseudomonas fluorescens strain A506 and Pantoea agglomerans strains C9-1 and E325). Maximum stigma age supporting bacterial multiplication decreased as temperature increased, and was reduced by pollination. Stigmas were receptive to bacteria at ages older than previously reported, probably due to less interference from indigenous organisms. The study revealed antagonist limitations that possibly affect field performance (e.g., the inability of strain A506 to grow on relatively old stigmas conducive to the pathogen). Such deficiencies could be overcome by selecting other antagonists or using antagonist mixtures in the orchard.

17.
Br J Ophthalmol ; 87(5): 609-14, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12714405

RESUMO

AIMS: To explore the relation between lesion composition as assessed by fundus photography and fluorescein angiography with clinical measures of vision in eyes of patients with age related macular degeneration (AMD). METHODS: A standardised visual function assessment along with colour stereo pair fundus photography was carried out in both eyes of 58 subjects with a confirmed clinical diagnosis of AMD. The size, location, and composition of the macular lesion (blood, exudate, subretinal fluid, pigment, membrane, atrophy, and fibrosis) were measured on the colour photographs using computer assisted image analysis. Of the 58 subjects, 44 also had concurrent fluorescein angiography. Classic and occult choroidal neovascularisation (CNV), blood, blocked fluorescence, fibrosis, geographic atrophy, and the total area of abnormal fluorescence were measured. Multiple linear regression was used to examine the relation between clinical measures of vision and the location and extent of lesion components identified by both colour and fluorescein image capture. RESULTS: The composition of the macular lesion strongly influenced visual function, with atrophy (p=0.001) and fibrosis (p=0.002) accounting for most of the variation. When the location of the lesion with respect to the fovea was examined, fibrosis within the fovea significantly influenced all clinical measures of vision (p=0.008). The regression model selected the total area of abnormal fluorescence and a composite parameter (a semiquantitative measure of the following characteristics: atrophy, exudates, blood, and fibrosis ) from colour photography (r(2) =0.52) as the variables that explained most of the variation in clinical measures of vision. CONCLUSIONS: The composition and extent of the macular lesion strongly influences visual function in eyes with AMD. Both colour photography and angiography yielded information, which together explained considerably more of the variation in the clinical measures of vision than either on its own.


Assuntos
Olho/patologia , Degeneração Macular/patologia , Visão Ocular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Neovascularização de Coroide/patologia , Sensibilidades de Contraste/fisiologia , Olho/fisiopatologia , Feminino , Fibrose , Angiofluoresceinografia/métodos , Fóvea Central/patologia , Humanos , Macula Lutea/patologia , Degeneração Macular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Atrofia Óptica/patologia , Leitura , Análise de Regressão , Acuidade Visual/fisiologia
19.
Pediatr Infect Dis J ; 20(10): 973-80, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11642632

RESUMO

INTRODUCTION: The objectives of this study were to evaluate the safety and immunogenicity of a new combination vaccine (DTaP-HB-IPV) containing diphtheria, tetanus, acellular pertussis and hepatitis B (HB) and a new inactivated poliovirus vaccine (IPV) manufactured by GlaxoSmithKline (GSK). This vaccine was given in an all IPV or sequential IPV and oral polio vaccine (OPV) schedule. Another combination vaccine, DTaP-HB (GSK), was similarly evaluated given with OPV or IPV. METHODS: Four hundred infants were randomized into one of four study groups and immunized at 2, 4 and 6 months of age. Group A received three doses of DTaP-HB-IPV; Group B received DTaP-HB-IPV at 2 and 4 months and DTaP-HB with OPV (Orimune) at 6 months; Group C received three doses of DTaP-HB with licensed IPV (IPOL) administered separately; Group D received separate doses of OPV, DTaP (Infanrix; GSK) and HB (Engerix; GSK). All subjects received conjugate Haemophilus influenzae type b vaccine (Hib) (OmniHIB) at 2, 4 and 6 months of age given at a separate injection site. Subjects who returned at 12 to 18 months of age (229) received booster immunization with DTaP and Hib. Safety was evaluated after each vaccine dose. Blood was drawn before the first dose and one month after the third dose as well as before and after the booster dose. RESULTS: There were no vaccine-related serious adverse events in any group after any vaccine dose. Minor systemic and local adverse events were also not significantly different among the four groups after any dose. There were no differences in the immune response rates for Hib, HB, polio (types 1, 2 and 3), diphtheria, tetanus or pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin) among groups, although there were some quantitative differences in specific antibody titers among groups. DTaP-HB-IPV and DTaP-HB combination vaccines had safety and immunogenicity equivalent to those of standard individually administered vaccines. The new IPV was not inferior to IPOL. CONCLUSION: Use of the pentavalent combination vaccine would greatly reduce the number of required injections during the first 2 years of life, thereby simplifying the immunization schedule, enhancing compliance and facilitating acceptance of additional injections engendered by introduction of newer vaccines.


Assuntos
Vacinas contra Difteria, Tétano e Coqueluche Acelular/efeitos adversos , Vacinas contra Difteria, Tétano e Coqueluche Acelular/imunologia , Vacinas contra Hepatite B/efeitos adversos , Vacinas contra Hepatite B/imunologia , Vacina Antipólio de Vírus Inativado/efeitos adversos , Vacina Antipólio de Vírus Inativado/imunologia , Vacinas contra Difteria, Tétano e Coqueluche Acelular/administração & dosagem , Vacinas contra Hepatite B/administração & dosagem , Humanos , Imunização Secundária/efeitos adversos , Lactente , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacinas Combinadas/efeitos adversos , Vacinas Combinadas/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA