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1.
Heliyon ; 9(11): e22139, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38045167

RESUMO

Synchrotron X-ray imaging and spectroscopy techniques were used for studying changes during post-harvest storage of food grains. Three varieties (AAC Spitfire, CDC Defy, and AAC Stronghold) of the Canada Western Amber Durum (CWAD) wheat class were stored for five weeks at 17 % moisture content (wb). Control (dry) and stored moistened seeds were analyzed for biochemical and nutritional changes using synchrotron bulk X-ray fluorescence spectroscopy (SR-XRF), X-ray fluorescence imaging (SR-XFI), and mid-infrared (mid-IR) spectroscopy at the Canadian Light Source (CLS), Saskatoon, SK. All varieties of durum wheat were spoiled at the end of five week, and AAC Spitfire and CDC Defy varieties were most affected in nutritional composition and their distribution than AAC Stronghold. Variable response to changes in biochemical and nutrition were found in all three spoiled varieties of the same durum wheat class.

2.
Open Forum Infect Dis ; 10(5): ofad108, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37152187

RESUMO

Background: We report outcomes and novel characterization of a unique cohort of 42 individuals with persistently indeterminate human immunodeficiency virus (HIV) status, the majority of whom are HIV viral controllers. Methods: Eligible individuals had indeterminate or positive HIV serology, but persistently undetectable HIV ribonucleic acid (RNA) by commercial assays and were not taking antiretroviral therapy (ART). Routine investigations included HIV Western blot, HIV viral load, qualitative HIV-1 deoxyribonucleic acid (DNA), coinfection screen, and T-cell quantification. Research assays included T-cell activation, ART measurement, single-copy assays detecting HIV-1 RNA and DNA, and plasma cytokine quantification. Human immunodeficiency virus seropositivity was defined as ≥3 bands on Western blot; molecular positivity was defined as detection of HIV RNA or DNA. Results: Human immunodeficiency virus infection was excluded in 10 of 42 referrals, remained unconfirmed in 2 of 42, and was confirmed in 30 of 42, who were identified as HIV elite controllers (ECs), normal CD4 T-cell counts (median 820/mL, range 805-1336), and normal CD4/CD8 ratio (median 1.8, range 1.2-1.9). Elite controllers had a median duration of elite control of 6 years (interquartile range = 4-14). Antiretroviral therapy was undetected in all 23 subjects tested. Two distinct categories of ECs were identified: molecular positive (n = 20) and molecular negative (n = 10). Conclusions: Human immunodeficiency virus status was resolved for 95% of referrals with the majority diagnosed as EC. The clinical significance of the 2 molecular categories among ECs requires further investigation.

3.
HIV Med ; 24(7): 838-844, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36895097

RESUMO

OBJECTIVE: Our objectives were to investigate the recent frequency of cerebrospinal fluid (CSF) HIV RNA escape and other CSF viral nucleic acid detection in people with HIV with neurological symptoms and to assess associated clinical factors. METHOD: This was a retrospective cohort analysis of people with HIV who underwent CSF examination for clinical indications between 2017 and 2022. Individuals were identified from pathology records, and clinical data were recorded. CSF HIV RNA escape was defined as CSF HIV RNA concentrations greater than in plasma. CSF viral screen included herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV), Epstein Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and JC virus. When cases were detected in five or more people with HIV, associated clinical factors were assessed using linear regression modelling. RESULTS: CSF HIV RNA escape was observed in 19 of 114 individuals (17%) and was associated with the presence of HIV drug resistance mutations and non-integrase strand transfer inhibitor-based antiretroviral therapy (p < 0.05 for all) when compared to people with HIV without escape. Positive viral nucleic acid testing included EBV (n = 10), VZV (3), CMV (2), HHV-6 (2) and JC virus (4). Detectable CSF EBV was not considered related to neurological symptoms and was associated with concomitant CSF infections in eight of ten individuals and with CSF pleocytosis, previous AIDS, lower nadir and current CD4 T-cell count (p < 0.05 for all). CONCLUSION: In people with HIV with neurological symptoms, the frequency of CSF HIV RNA escape remains similar to that in historical reports. Detectable EBV viral nucleic acid in the CSF was observed frequently and, in the absence of clinical manifestations, may be a consequence of CSF pleocytosis.


Assuntos
Infecções por Citomegalovirus , Infecções por Vírus Epstein-Barr , Infecções por HIV , Infecções por Herpesviridae , Humanos , Infecções por Herpesviridae/líquido cefalorraquidiano , Infecções por Herpesviridae/diagnóstico , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/complicações , Estudos Retrospectivos , Leucocitose/complicações , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Herpesvirus Humano 3/genética , Citomegalovirus , RNA , Líquido Cefalorraquidiano , DNA Viral
4.
Lancet Infect Dis ; 23(6): e218-e226, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36773621

RESUMO

A 48-year-old man with poorly controlled HIV presented with severe human monkeypox virus (hMPXV) infection, having completed 2 weeks of tecovirimat at another hospital. He had painful, ulcerating skin lesions on most of his body and oropharyngeal cavity, with subsequent Ludwig's angina requiring repeated surgical interventions. Despite commencing a second, prolonged course of tecovirimat, he did not objectively improve, and new lesions were still noted at day 24. Discussion at the UK National Health Service England High Consequence Infectious Diseases Network recommended the use of 3% topical and then intravenous cidofovir, which was given at 5 mg/kg; the patient made a noticeable improvement after the first intravenous dose. He received further intravenous doses at 7 days and 21 days after the dose and was discharged at day 52. Cidofovir is not licensed for use in treatment of hMPXV infection. Data for cidofovir use in hMPXV are restricted to studies in animals. Four other documented cases of cidofovir use against hMPXV have been reported in the USA in 2022, but we present its first use in the UK. The scarcity of studies into the use of cidofovir in this condition clearly shows the need for robust studies to assess efficacy, optimum dosage, timing, and route of administration.


Assuntos
Infecções por HIV , Organofosfonatos , Masculino , Humanos , Pessoa de Meia-Idade , Cidofovir/uso terapêutico , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Organofosfonatos/uso terapêutico , Medicina Estatal , Citosina/uso terapêutico , Antivirais/uso terapêutico
5.
Int J Infect Dis ; 126: 48-53, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36410691

RESUMO

OBJECTIVES: Since May 2022, cases of human monkeypox virus (hMPXV) with human-to-human cross-transmission have significantly increased in nonendemic countries. Our aim was to characterize diagnostic features of patients with confirmed and possible monkeypox to guide future risk stratification and to describe a virtual care model. METHODS: We performed a retrospective case-control study of 140 patients assessed and screened for suspected monkeypox; on hMPXV polymerase chain reaction testing, 70 were confirmed positive, and 70 were negative. Data were compared to generate odds ratios of demographic and clinical features. RESULTS: Patients who tested positive were predominantly cis-male (99%) and self-identified as gay, bisexual, and other men who have sex with men (94%). Lymphadenopathy at presentation was associated with a higher likelihood of a positive result (odds ratio [OR] 7.69 [95% confidence interval (CI) 3.58, 16.51]). Patients who tested positive were more likely to have a rash affecting the genital (OR 5.38 [95% CI 2.57, 11.23]) or buttocks/perianal region (OR 3.79 [1.70, 8.45]) than negative controls. A total of 79% of patients were engaged with a virtual ward follow-up. CONCLUSION: These data can inform a risk-based approach to the management of suspected monkeypox in gay, bisexual, and other men who have sex with men populations. Lymphadenopathy at presentation and the location of the rash were more associated with a positive hMPXV result. Health authorities can consider a virtual ward approach in the hMPHXV outbreak.


Assuntos
Exantema , Linfadenopatia , Minorias Sexuais e de Gênero , Humanos , Masculino , Estudos de Casos e Controles , Estudos Retrospectivos , /epidemiologia , Homossexualidade Masculina , Londres
7.
J Synchrotron Radiat ; 28(Pt 3): 961-969, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33950004

RESUMO

A new diffraction beamline for materials science has been built at the Canadian Light Source synchrotron. The X-ray source is an in-vacuum wiggler with a 2.5 T peak magnetic field at 5.2 mm gap. The optical configuration includes a toroidal mirror, a single side-bounce Bragg monochromator, and a cylindrical mirror, producing a sub-150 µm vertical × 500 µm horizontal focused beam with a photon energy range of 7-22 keV and a flux of 1012 photons per second at the sample position. Three endstations are currently open to general users, and the techniques available include high-resolution powder diffraction, small molecule crystallography, X-ray reflectivity, in situ rapid thermal annealing, and SAXS/WAXS. The beamline design parameters, calculated and measured performance, and initial experimental results are presented to demonstrate the capabilities for materials science.

8.
Clin Infect Dis ; 72(1): 82-89, 2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-32634822

RESUMO

BACKGROUND: Understanding nosocomial acquisition, outbreaks, and transmission chains in real time will be fundamental to ensuring infection-prevention measures are effective in controlling coronavirus disease 2019 (COVID-19) in healthcare. We report the design and implementation of a hospital-onset COVID-19 infection (HOCI) surveillance system for an acute healthcare setting to target prevention interventions. METHODS: The study took place in a large teaching hospital group in London, United Kingdom. All patients tested for SARS-CoV-2 between 4 March and 14 April 2020 were included. Utilizing data routinely collected through electronic healthcare systems we developed a novel surveillance system for determining and reporting HOCI incidence and providing real-time network analysis. We provided daily reports on incidence and trends over time to support HOCI investigation and generated geotemporal reports using network analysis to interrogate admission pathways for common epidemiological links to infer transmission chains. By working with stakeholders the reports were co-designed for end users. RESULTS: Real-time surveillance reports revealed changing rates of HOCI throughout the course of the COVID-19 epidemic, key wards fueling probable transmission events, HOCIs overrepresented in particular specialties managing high-risk patients, the importance of integrating analysis of individual prior pathways, and the value of co-design in producing data visualization. Our surveillance system can effectively support national surveillance. CONCLUSIONS: Through early analysis of the novel surveillance system we have provided a description of HOCI rates and trends over time using real-time shifting denominator data. We demonstrate the importance of including the analysis of patient pathways and networks in characterizing risk of transmission and targeting infection-control interventions.


Assuntos
COVID-19 , Hospitais , Humanos , Londres , SARS-CoV-2 , Reino Unido
9.
Lancet Microbe ; 1(7): e300-e307, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32964211

RESUMO

BACKGROUND: Access to rapid diagnosis is key to the control and management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Laboratory RT-PCR testing is the current standard of care but usually requires a centralised laboratory and significant infrastructure. We describe our diagnostic accuracy assessment of a novel, rapid point-of-care real time RT-PCR CovidNudge test, which requires no laboratory handling or sample pre-processing. METHODS: Between April and May, 2020, we obtained two nasopharyngeal swab samples from individuals in three hospitals in London and Oxford (UK). Samples were collected from three groups: self-referred health-care workers with suspected COVID-19; patients attending emergency departments with suspected COVID-19; and hospital inpatient admissions with or without suspected COVID-19. For the CovidNudge test, nasopharyngeal swabs were inserted directly into a cartridge which contains all reagents and components required for RT-PCR reactions, including multiple technical replicates of seven SARS-CoV-2 gene targets (rdrp1, rdrp2, e-gene, n-gene, n1, n2 and n3) and human ribonuclease P (RNaseP) as sample adequacy control. Swab samples were tested in parallel using the CovidNudge platform, and with standard laboratory RT-PCR using swabs in viral transport medium for processing in a central laboratory. The primary analysis was to compare the sensitivity and specificity of the point-of-care CovidNudge test with laboratory-based testing. FINDINGS: We obtained 386 paired samples: 280 (73%) from self-referred health-care workers, 15 (4%) from patients in the emergency department, and 91 (23%) hospital inpatient admissions. Of the 386 paired samples, 67 tested positive on the CovidNudge point-of-care platform and 71 with standard laboratory RT-PCR. The overall sensitivity of the point-of-care test compared with laboratory-based testing was 94% (95% CI 86-98) with an overall specificity of 100% (99-100). The sensitivity of the test varied by group (self-referred healthcare workers 94% [95% CI 85-98]; patients in the emergency department 100% [48-100]; and hospital inpatient admissions 100% [29-100]). Specificity was consistent between groups (self-referred health-care workers 100% [95% CI 98-100]; patients in the emergency department 100% [69-100]; and hospital inpatient admissions 100% [96-100]). Point of care testing performance was similar during a period of high background prevalence of laboratory positive tests (25% [95% 20-31] in April, 2020) and low prevalence (3% [95% 1-9] in inpatient screening). Amplification of viral nucleocapsid (n1, n2, and n3) and envelope protein gene (e-gene) were most sensitive for detection of spiked SARS-CoV-2 RNA. INTERPRETATION: The CovidNudge platform was a sensitive, specific, and rapid point of care test for the presence of SARS-CoV-2 without laboratory handling or sample pre-processing. The device, which has been implemented in UK hospitals since May, 2020, could enable rapid decisions for clinical care and testing programmes. FUNDING: National Institute of Health Research (NIHR) Imperial Biomedical Research Centre, NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at Oxford University in partnership with Public Health England, NIHR Biomedical Research Centre Oxford, and DnaNudge.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Humanos , Testes Imediatos , RNA Viral/genética , Sensibilidade e Especificidade
10.
Artigo em Inglês | MEDLINE | ID: mdl-32457227

RESUMO

OBJECTIVE: To describe a novel case of coronavirus disease 2019 (COVID-19)-associated acute necrotizing encephalopathy (ANE) in a patient with aplastic anemia where there was early brain stem-predominant involvement. METHODS: Evaluation of cause, clinical symptoms, and treatment response. RESULTS: A 59-year-old woman with a background of transfusion-dependent aplastic anemia presented with seizures and reduced level of consciousness 10 days after the onset of subjective fever, cough, and headache. Nasopharyngeal swab testing for severe acute respiratory syndrome coronavirus (SARS-CoV-2) was positive, and CT during admission demonstrated diffuse swelling of the brain stem. She required intubation and mechanical ventilation for airway protection, given her reduced level of consciousness. The patient's condition deteriorated, and MRI on day 6 demonstrated worsening brain stem swelling with symmetrical hemorrhagic lesions in the brain stem, amygdalae, putamina, and thalamic nuclei. Appearances were consistent with hemorrhagic ANE with early brain stem involvement. The patient showed no response to steroid therapy and died on the eighth day of admission. CONCLUSIONS: COVID-19 may be associated with an acute severe encephalopathy and, in this case, was considered most likely to represent an immune-mediated phenomenon. As the pandemic continues, we anticipate that the spectrum of neurologic presentation will broaden. It will be important to delineate the full clinical range of emergent COVID-19-related neurologic disease.


Assuntos
Anemia Aplástica/complicações , Infecções por Coronavirus/complicações , Leucoencefalite Hemorrágica Aguda/etiologia , Pneumonia Viral/complicações , Tonsila do Cerebelo/diagnóstico por imagem , Anemia Aplástica/terapia , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Edema Encefálico/fisiopatologia , Edema Encefálico/terapia , Tronco Encefálico/diagnóstico por imagem , COVID-19 , Infecções por Coronavirus/terapia , Dexametasona/uso terapêutico , Imagem de Difusão por Ressonância Magnética , Evolução Fatal , Feminino , Glucocorticoides/uso terapêutico , Humanos , Hemorragias Intracranianas/diagnóstico por imagem , Hemorragias Intracranianas/etiologia , Hemorragias Intracranianas/fisiopatologia , Leucoencefalite Hemorrágica Aguda/diagnóstico por imagem , Leucoencefalite Hemorrágica Aguda/fisiopatologia , Leucoencefalite Hemorrágica Aguda/terapia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Pandemias , Transfusão de Plaquetas , Pneumonia Viral/terapia , Hemorragia Putaminal/diagnóstico por imagem , Hemorragia Putaminal/etiologia , Hemorragia Putaminal/fisiopatologia , Respiração Artificial , Convulsões/etiologia , Núcleos Talâmicos/diagnóstico por imagem , Tomografia Computadorizada por Raios X
13.
Physiol Plant ; 162(3): 316-332, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28857201

RESUMO

Wheat (Triticum aestivum L.) is the largest cereal crop grown in Western Canada where drought during late vegetative and seed filling stages affects plant development and yield. To identify new physiochemical markers associated with drought tolerance, epidermal characteristics of the flag leaf of two wheat cultivars with contrasting drought tolerance were investigated. The drought resistant 'Stettler' had a lower drought susceptibility index, greater harvest index and water-use efficiency than the susceptible 'Superb'. Furthermore, flag leaf width, relative water content and leaf roll were significantly greater in Stettler than in Superb at moderate drought stress (MdS). Visible differences in epicuticular wax density on the adaxial flag leaf surfaces and larger bulliform cells were identified in Stettler as opposed to Superb. Mid-infrared attenuated total internal reflectance spectra revealed that Stettler flag leaves had increased asymmetric and symmetric CH2 but reduced carbonyl esters on its adaxial leaf surface compared to Superb under MdS. X-ray fluorescence spectra revealed a significant increase in total flag leaf Zn concentrations in Stettler in response to MdS. Such information on the microstructural and chemical features of flag leaf may have potential as markers for drought tolerance and thereby accelerate the selection and release of more drought-resistant cultivars.


Assuntos
Secas , Folhas de Planta/metabolismo , Triticum/metabolismo , Ceras/metabolismo , Adaptação Fisiológica , Microscopia Eletrônica de Varredura , Folhas de Planta/anatomia & histologia , Folhas de Planta/ultraestrutura , Especificidade da Espécie , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Fisiológico , Síncrotrons , Triticum/anatomia & histologia , Triticum/classificação , Água/metabolismo , Ceras/química , Espectroscopia por Absorção de Raios X
14.
Sci Rep ; 7(1): 13658, 2017 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-29057945

RESUMO

There is a global need for HIV viral load point-of-care (PoC) assays to monitor patients receiving antiretroviral therapy. UNICORN was the first study of an off-label protocol using whole blood finger-prick samples tested with and without a simple three minute spin using a clinic-room microcentrifuge. Two PoC assays were evaluated in 40 HIV-positive participants, 20 with detectable and 20 with undetectable plasma viral load (pVL) (<20 copies/ml). Using 100 µl finger-prick blood samples, the Cepheid Xpert HIV-1 Viral Load and HIV-1 Qual cartridges were compared with laboratory pVL assessment (TaqMan, Roche). For participants with undetectable viraemia by TaqMan, there was poor concordance without centrifugation with the TaqMan platform with only 40% 'undetectable' using Xpert VL and 25% 'not detected' using the Qual assay. After a 3 minute spin, 100% of samples were undetectable using either assay, showing full concordance with the TaqMan assay. Defining a lower limit of detection of 1000 copies/ml when including a spin, there was 100% concordance with the TaqMan platform with strong correlation (rho 0.95 and 0.94; p < 0.0001 for both assays). When including a simple microcentrifugation step, finger-prick PoC testing was a quick and accurate approach for assessing HIV viraemia, with excellent concordance with validated laboratory approaches.


Assuntos
Coleta de Amostras Sanguíneas , Infecções por HIV/sangue , Infecções por HIV/virologia , HIV-1 , Testes Imediatos , Carga Viral , Adolescente , Adulto , Idoso , Coleta de Amostras Sanguíneas/métodos , Centrifugação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Carga Viral/instrumentação , Carga Viral/métodos , Adulto Jovem
15.
PLoS One ; 11(12): e0167682, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27973564

RESUMO

The success of peripheral nerve regeneration is highly dependent on the regrowth of axons within the endoneurial basal lamina tubes that promote target-oriented pathfinding and appropriate reinnervation. Restoration of nerve continuity at this structural level after nerve transection injury by direct repair and nerve grafting remains a major surgical challenge. Recently, biological approaches that alter the balance of growth inhibitors and promoters in nerve have shown promise to improve appropriate axonal regeneration and recovery of peripheral nerve function. Chondroitin sulfate proteoglycans (CSPGs) are known inhibitors of axonal growth. This growth inhibition is mainly associated with a CSPG's glycosaminoglycan chains. Enzymatic degradation of these chains with chondroitinase eliminates this inhibitory activity and, when applied in vivo, can improve the outcome of nerve repair. To date, these encouraging findings were obtained with chondroitinase ABC (a pan-specific chondroitinase). The aim of this study was to examine the distribution of CSPG subtypes in rodent, rabbit, and human peripheral nerve and to test more selective biological enzymatic approaches to improve appropriate axonal growth within the endoneurium and minimize aberrant growth. Here we provide evidence that the endoneurium, but not the surrounding epineurium, is rich in CSPGs that have glycosaminoglycan chains readily degraded by chondroitinase C. Biochemical studies indicate that chondroitinase C has degradation specificity for 6-sulfated glycosaminoglycans found in peripheral nerve. We found that chondroitinase C degrades and inactivates inhibitory CSPGs within the endoneurium but not so much in the surrounding nerve compartments. Cryoculture bioassays (neurons grown on tissue sections) show that chondroitinase C selectively and significantly enhanced neuritic growth associated with the endoneurial basal laminae without changing growth-inhibiting properties of the surrounding epineurium. Interestingly, chondroitinase ABC treatment increased greatly the growth-promoting properties of the epineurial tissue whereas chondroitinase C had little effect. Our evidence indicates that chondroitinase C effectively degrades and inactivates inhibitory CSPGs present in the endoneurial Schwann cell basal lamina and does so more specifically than chondroitinase ABC. These findings are discussed in the context of improving nerve repair and regeneration and the growth-promoting properties of processed nerve allografts.


Assuntos
Condroitina ABC Liase/fisiologia , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Sulfatos de Condroitina/metabolismo , Regeneração Nervosa , Neurônios/metabolismo , Sistema Nervoso Periférico/metabolismo , Animais , Anticorpos/química , Axônios/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peso Molecular , Neurônios/transplante , Nervos Periféricos/metabolismo , Coelhos , Ratos , Ratos Sprague-Dawley
16.
Lab Invest ; 96(10): 1105-15, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27617404

RESUMO

Neurofibromas, which are benign Schwann cell tumors, are the hallmark feature in the autosomal dominant condition neurofibromatosis 1 (NF1) and are associated with biallelic loss of NF1 gene function. There is a need for effective therapies for neurofibromas, particularly the larger, plexiform neurofibromas. Tissue culture is an important tool for research. However, it is difficult to derive enriched human Schwann cell cultures, and most enter replicative senescence after 6-10 passages, impeding cell-based research in NF1. Through exogenous expression of human telomerase reverse transcriptase and murine cyclin-dependent kinase (mCdk4), normal (NF1 wild-type), neurofibroma-derived Schwann cells heterozygous for NF1 mutation, and neurofibroma-derived Schwann cells homozygous for NF1 mutation were immortalized, including some matched samples from the same NF1 patient. Initial experiments employed retroviral vectors, while subsequent work utilized lentiviral vectors carrying these genes because of improved efficiency. Expression of both transgenes was required for immortalization. Molecular and immunohistochemical analysis indicated that these cell lines are of Schwann cell lineage and have a range of phenotypes, many of which are consistent with their primary cultures. This is the first report of immortalization and detailed characterization of multiple human NF1 normal nerve and neurofibroma-derived Schwann cell lines, which will be highly useful research tools to study NF1 and other Schwann tumor biology and conditions.


Assuntos
Técnicas de Cultura de Células , Neurofibromatose 1 , Células de Schwann , Animais , Linhagem Celular Tumoral , Quinase 4 Dependente de Ciclina/genética , Humanos , Camundongos , Transplante de Neoplasias , Telomerase/genética
17.
Front Microbiol ; 7: 910, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27445995

RESUMO

Fusarium head blight (FHB) is a serious disease of wheat worldwide. Cultivar resistance to FHB depends on biochemical factors that confine the pathogen spread in spikes. Breeding for cultivar resistance is considered the most practical way to manage this disease. In this study, different spectroscopy and microscopy techniques were applied to discriminate resistance in wheat genotypes against FHB. Synchrotron-based spectroscopy and imaging techniques, including focal plane array infrared and X-ray fluorescence (XRF) spectroscopy were used to understand changes in biochemical and nutrients in rachis following FHB infection. Sumai3 and Muchmore were used to represent resistant and susceptible cultivars to FHB, respectively, in this study. The histological comparison of rachis showed substantial differences in the cell wall thickness between the cultivars after infection. Synchrotron-based infrared imaging emphasized substantial difference in biochemical composition of rachis samples between the two cultivars prior to visible symptoms; in the resistant Sumai3, infrared bands representing lignin and hemicellulose were stronger and more persistent compared to the susceptible cultivar. These bands may be the candidates of biochemical markers for FHB resistance. Focal plane array infrared imaging (FPA) spectra from the rachis epidermis and vascular bundles revealed a new band (1710 cm(-1)) related to the oxidative stress on the susceptible cultivar only. XRF spectroscopy data revealed differences in nutrients composition between cultivars, and between controls and inoculated samples, with substantial increases observed for Ca, K, Mn, Fe, Zn, and Si in the resistant cultivar. These nutrients are related to cell wall stability, metabolic process, and plant defense mechanisms such as lignification pathway and callose deposition. The combination of cell wall composition and lignification plays a role in the mechanism of type II host resistance to FHB. Biochemical profiling using the synchrotron-based spectroscopy holds potential for screening wheat genotypes for FHB resistance.

18.
Sci Rep ; 6: 22510, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26936144

RESUMO

The properties of epitaxial silicene monolayers on Ag(111) at various levels of oxidation are determined through complementary density functional theory calculations and soft X-ray spectroscopy experiments. Our calculations indicate that moderate levels of oxidation do not cause a significant bandgap opening in the epitaxial silicene monolayer, suggesting that oxygen functionalization is not a viable mechanism for bandgap tuning while the silicene monolayer remains on its metallic substrate. In addition, moderate oxidation is calculated to strongly distort the hexagonal Si lattice, causing it to cluster in regions of highest oxygen adatom concentration but retain its 2D sheet structure. However, our experiments reveal that beam-induced oxidation is consistent with the formation of islands of bulk-like SiO2. Complete exposure of the monolayer to ambient conditions results in a fully oxidized sample that closely resembles bulk SiO2, of which a significant portion is completely detached from the substrate.


Assuntos
Compostos de Silício/química , Prata/química , Oxirredução
19.
PLoS One ; 11(3): e0151497, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26974653

RESUMO

Chlamydia trachomatis (Ct) serological studies in populations could help monitor changes in lifetime cumulative risk of infection. We developed a double-antigen sandwich ELISA based on the Ct-specific Pgp3 antigen, then tested blind stored sera from over 800 participants in a New Zealand birth cohort from Dunedin at ages 26, 32 and 38. The double-antigen sandwich ELISA was more sensitive than our previously characterised indirect Pgp3 ELISA. Pgp3 antibody was detected more often in women compared to men and correlated with increasing numbers of sexual partners, self-reported Ct, and younger age at sexual debut in both women and men. At age 26, 24.1% (99/411) of women were Pgp3 seropositive, as were 79.5% (35/44) of those reporting Ct infection; Pgp3 antibody persisted to age 38 in 96.5% (83/86). In men at age 26, the figures were 10.7% (47/442) and 25.0% (6/24), respectively, with high (83.9%) antibody persistence to age 38. At age 38, among those Pgp3 seropositive, 63.3% of women and 83.1% of men had not reported Ct infection. Thus, Ct-specific Pgp3 antibody was detected in most women reporting Ct infection and correlated with risk of infection in those who did not, with most infections remaining undetected. As this antibody persisted for at least twelve years in 96% of these women, serology could be used to evaluate Ct prevention programmes among women.


Assuntos
Anticorpos Antibacterianos/imunologia , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/imunologia , Autorrelato , Comportamento Sexual , Adulto , Antígenos de Bactérias/imunologia , Área Sob a Curva , Proteínas de Bactérias/imunologia , Infecções por Chlamydia/sangue , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Nova Zelândia , Curva ROC , Fatores de Risco , Sensibilidade e Especificidade
20.
Nat Commun ; 6: 10035, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26602295

RESUMO

Active and durable electrocatalysts for methanol oxidation reaction are of critical importance to the commercial viability of direct methanol fuel cell technology. Unfortunately, current methanol oxidation electrocatalysts fall far short of expectations and suffer from rapid activity degradation. Here we report platinum-nickel hydroxide-graphene ternary hybrids as a possible solution to this long-standing issue. The incorporation of highly defective nickel hydroxide nanostructures is believed to play the decisive role in promoting the dissociative adsorption of water molecules and subsequent oxidative removal of carbonaceous poison on neighbouring platinum sites. As a result, the ternary hybrids exhibit exceptional activity and durability towards efficient methanol oxidation reaction. Under periodic reactivations, the hybrids can endure at least 500,000 s with negligible activity loss, which is, to the best of our knowledge, two to three orders of magnitude longer than all available electrocatalysts.


Assuntos
Grafite/química , Hidróxidos/química , Metanol/metabolismo , Nanoestruturas/ultraestrutura , Níquel/química , Oxirredução , Platina/química , Catálise , Fontes de Energia Elétrica , Técnicas Eletroquímicas , Microscopia Eletrônica
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