Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
1.
J Laryngol Otol ; 137(3): 312-318, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35172908

RESUMO

BACKGROUND: In adults, the solitary lateral cystic neck mass remains a diagnostic challenge with little solid material to target for cytology and few clues on imaging modalities to suggest underlying malignancy. METHOD: This study was a retrospective review of patients presenting with a lateral cystic neck mass to a tertiary academic head and neck centre over a 10-year period. RESULTS: A total of 25 of 157 cystic lesions were subsequently malignant on paraffin section histopathology, with the youngest patient being 42 years. In the age cohort over 40 years, 30 per cent of males and 10 per cent of females were diagnosed with malignancy. The ipsilateral palatine tonsil was the most common primary site (50 per cent). A total of 85 per cent of cases demonstrated integrated human papillomavirus infection. Age, male sex and alcohol were significant risk factors on univariate analysis. Ultrasound-guided fine needle aspiration cytology and magnetic resonance imaging represented the most accurate pre-open biopsy tests. CONCLUSION: The authors of this study advocate for a risk-stratified, evidence-based workup in patients with solitary lateral cystic neck mass in order to optimise timely diagnosis.


Assuntos
Branquioma , Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Feminino , Humanos , Adulto , Masculino , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Branquioma/diagnóstico , Branquioma/patologia , Carcinoma de Células Escamosas/patologia , Diagnóstico Diferencial , Pescoço/diagnóstico por imagem , Pescoço/patologia
2.
J Geophys Res Space Phys ; 127(12): e2022JA030398, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37032655

RESUMO

We analyze observations of a solar energetic particle (SEP) event at Rosetta's target comet 67P/Churyumov-Gerasimenko during 6-10 March 2015. The comet was 2.15 AU from the Sun, with the Rosetta spacecraft approximately 70 km from the nucleus placing it deep inside the comet's coma and allowing us to study its response. The Eastern flank of an interplanetary coronal mass ejection (ICME) also encountered Rosetta on 6 and 7 March. Rosetta Plasma Consortium data indicate increases in ionization rates, and cometary water group pickup ions exceeding 1 keV. Increased charge exchange reactions between solar wind ions and cometary neutrals also indicate increased upstream neutral populations consistent with enhanced SEP induced surface activity. In addition, the most intense parts of the event coincide with observations interpreted as an infant cometary bow shock, indicating that the SEPs may have enhanced the formation and/or intensified the observations. These solar transient events may also have pushed the cometopause closer to the nucleus. We track and discuss characteristics of the SEP event using remote observations by SOHO, WIND, and GOES at the Sun, in situ measurements at Solar Terrestrial Relations Observatory Ahead, Mars and Rosetta, and ENLIL modeling. Based on its relatively prolonged duration, gradual and anisotropic nature, and broad angular spread in the heliosphere, we determine the main particle acceleration source to be a distant ICME which emerged from the Sun on 6 March 2015 and was detected locally in the Martian ionosphere but was never encountered by 67P directly. The ICME's shock produced SEPs for several days which traveled to the in situ observation sites via magnetic field line connections.

3.
J Laryngol Otol ; : 1-6, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33138870

RESUMO

BACKGROUND: There are sparse data on the outcomes of endoscopic stapling of pharyngeal pouches. The Mersey ENT Trainee Collaborative compared regional practice against published benchmarks. METHODS: A 10-year retrospective analysis of endoscopic pharyngeal pouch surgery was conducted and practice was assessed against eight standards. Comparisons were made between results from the tertiary centre and other sites. RESULTS: A total of 225 procedures were performed (range of 1.2-9.2 cases per centre per year). All centres achieved 90 per cent resumption of oral intake within 2 days. All centres achieved less than 2-day hospital stays. Primary success (84 per cent (i.e. abandonment of endoscopic stapling in 16 per cent)), symptom resolution (83 per cent) and recurrence rates (13 per cent) failed to meet the standard across the non-tertiary centres. CONCLUSION: Endoscopic pharyngeal pouch stapling is a procedure with a low mortality and brief in-patient stay. There was significant variance in outcomes across the region. This raises the question of whether this service should become centralised and the preserve of either tertiary centres or sub-specialist practitioners.

4.
Diabet Med ; 36(11): 1367-1374, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31466128

RESUMO

AIM: To investigate the incretin axis in people with cystic fibrosis. METHODS: Adults with cystic fibrosis-related diabetes, cystic fibrosis without diabetes, and controls (adults without cystic fibrosis and without diabetes) underwent an oral glucose tolerance test and then a closely matched isoglycaemic i.v. glucose infusion. On each occasion, glucose, insulin, C-peptide, total and active glucagon-like peptide-1 and gastric inhibitory polypeptide responses were recorded and incremental areas under curves were calculated for 60 and 240 min. RESULTS: Five adults with cystic fibrosis-related diabetes, six with cystic fibrosis without diabetes and six controls, matched for age and BMI, completed the study. Glucose during oral glucose tolerance test closely matched those during isoglycaemic i.v. glucose infusion. The calculated incretin effect was similar in the control group and the cystic fibrosis without diabetes group (28% and 29%, respectively), but was lost in the cystic fibrosis-related diabetes group (cystic fibrosis-related diabetes vs control group: -6% vs 28%; p=0.03). No hyposecretion of glucagon-like peptide-1 or gastric inhibitory polypeptide was observed; conversely, 60-min incremental area under the curve for total glucagon-like peptide-1 was significantly higher in the cystic fibrosis-related diabetes group than in the control group [1070.4 (254.7) vs 694.97 (308.1); p=0.03] CONCLUSIONS: The incretin effect was lost in cystic fibrosis-related diabetes despite adequate secretion of the incretin hormones. These data support the concept that reduced incretin hormone insulinotropic activity contributes significantly to postprandial hyperglycaemia in cystic fibrosis-related diabetes.


Assuntos
Fibrose Cística/fisiopatologia , Diabetes Mellitus/fisiopatologia , Glucose/administração & dosagem , Hiperglicemia/fisiopatologia , Incretinas/sangue , Adulto , Peptídeo C/sangue , Fibrose Cística/complicações , Diabetes Mellitus/sangue , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/etiologia , Feminino , Polipeptídeo Inibidor Gástrico/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Glucose/metabolismo , Teste de Tolerância a Glucose , Humanos , Hiperglicemia/sangue , Infusões Intravenosas , Insulina/sangue , Masculino
5.
Science ; 364(6445)2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-30923171

RESUMO

Saturn's main ring system is associated with a set of small moons that either are embedded within it or interact with the rings to alter their shape and composition. Five close flybys of the moons Pan, Daphnis, Atlas, Pandora, and Epimetheus were performed between December 2016 and April 2017 during the ring-grazing orbits of the Cassini mission. Data on the moons' morphology, structure, particle environment, and composition were returned, along with images in the ultraviolet and thermal infrared. We find that the optical properties of the moons' surfaces are determined by two competing processes: contamination by a red material formed in Saturn's main ring system and accretion of bright icy particles or water vapor from volcanic plumes originating on the moon Enceladus.

6.
Science ; 362(6410)2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30287631

RESUMO

Saturn has a sufficiently strong dipole magnetic field to trap high-energy charged particles and form radiation belts, which have been observed outside its rings. Whether stable radiation belts exist near the planet and inward of the rings was previously unknown. The Cassini spacecraft's Magnetosphere Imaging Instrument obtained measurements of a radiation belt that lies just above Saturn's dense atmosphere and is decoupled from the rest of the magnetosphere by the planet's A- to C-rings. The belt extends across the D-ring and comprises protons produced through cosmic ray albedo neutron decay and multiple charge-exchange reactions. These protons are lost to atmospheric neutrals and D-ring dust. Strong proton depletions that map onto features on the D-ring indicate a highly structured and diverse dust environment near Saturn.

8.
J Laryngol Otol ; 131(12): 1065-1092, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29280695

RESUMO

BACKGROUND: The mainstay of management of epistaxis refractory to first aid and cautery is intranasal packing. This review aimed to identify evidence surrounding nasal pack use. METHOD: A systematic review of the literature was performed using standardised methodology. RESULTS: Twenty-seven eligible articles were identified relating to non-dissolvable packs and nine to dissolvable packs. Nasal packing appears to be more effective when applied by trained professionals. For non-dissolvable packs, the re-bleed rates for Rapid Rhino and Merocel were similar, but were higher with bismuth iodoform paraffin paste packing. Rapid Rhino packs were the most tolerated non-dissolvable packs. Evidence indicates that 96 per cent of re-bleeding occurs within the first 4 hours after nasal pack removal. Limited evidence suggests that dissolvable packs are effective and well tolerated by patients. There was a lack of evidence relating to: the duration of pack use, the economic effects of pack choice and the appropriate care setting for non-dissolvable packs. CONCLUSION: Rapid Rhino packs are the best tolerated, with efficacy equivalent to nasal tampons. FloSeal is easy to use, causes less discomfort and may be superior to Merocel in anterior epistaxis cases. There is no strong evidence to support prophylactic antibiotic use.


Assuntos
Epistaxe/terapia , Hemostáticos/uso terapêutico , Tampões Cirúrgicos , Adulto , Terapia Combinada , Eletrocoagulação , Primeiros Socorros , Humanos , Resultado do Tratamento
9.
Philos Trans A Math Phys Eng Sci ; 375(2097)2017 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-28554971

RESUMO

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'.

11.
J Laryngol Otol ; 129(9): 831-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26314318

RESUMO

BACKGROUND: Minimum health requirements exist for entry into the UK armed forces. Both pre-existing and iatrogenic ENT conditions may impact on an individual's medical fitness and their ability to enter the forces. METHODS: The relevant literature was examined and military otolaryngology advisors were interviewed in order to define the ENT-specific conditions that restrict an individual joining the armed forces. RESULTS: The ENT diseases and disabilities that inhibit an individual's ability to join the forces are described. Treatments that may facilitate or restrict recruitment are also discussed. CONCLUSION: Members of the armed forces operate in arduous environments and are required to pass a screening medical assessment before joining. Personnel may be isolated away from specialist care and therefore cannot be dependent on specialist devices or medicines. This paper aims to arm ENT specialists with occupational knowledge to enable them to correctly counsel patients and offer appropriate treatment.


Assuntos
Avaliação da Deficiência , Programas de Rastreamento , Militares , Otorrinolaringopatias/diagnóstico , Humanos , Otorrinolaringopatias/terapia , Educação de Pacientes como Assunto , Reino Unido
12.
Geophys Res Lett ; 41(5): 1382-1388, 2014 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25821276

RESUMO

We report on the first analysis of magnetospheric cusp observations at Saturn by multiple in situ instruments onboard the Cassini spacecraft. Using this we infer the process of reconnection was occurring at Saturn's magnetopause. This agrees with remote observations that showed the associated auroral signatures of reconnection. Cassini crossed the northern cusp around noon local time along a poleward trajectory. The spacecraft observed ion energy-latitude dispersions-a characteristic signature of the terrestrial cusp. This ion dispersion is "stepped," which shows that the reconnection is pulsed. The ion energy-pitch angle dispersions suggest that the field-aligned distance from the cusp to the reconnection site varies between ∼27 and 51 RS . An intensification of lower frequencies of the Saturn kilometric radiation emissions suggests the prior arrival of a solar wind shock front, compressing the magnetosphere and providing more favorable conditions for magnetopause reconnection. KEY POINTS: We observe evidence for reconnection in the cusp plasma at SaturnWe present evidence that the reconnection process can be pulsed at SaturnSaturn's cusp shows similar characteristics to the terrestrial cusp.

13.
Geophys Res Lett ; 41(20): 7011-7018, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26074639

RESUMO

On 26 September 2005, Cassini conducted its only close targeted flyby of Saturn's small, irregularly shaped moon Hyperion. Approximately 6 min before the closest approach, the electron spectrometer (ELS), part of the Cassini Plasma Spectrometer (CAPS) detected a field-aligned electron population originating from the direction of the moon's surface. Plasma wave activity detected by the Radio and Plasma Wave instrument suggests electron beam activity. A dropout in energetic electrons was observed by both CAPS-ELS and the Magnetospheric Imaging Instrument Low-Energy Magnetospheric Measurement System, indicating that the moon and the spacecraft were magnetically connected when the field-aligned electron population was observed. We show that this constitutes a remote detection of a strongly negative (∼ -200 V) surface potential on Hyperion, consistent with the predicted surface potential in regions near the solar terminator.

14.
Nature ; 496(7444): 193-5, 2013 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-23579676

RESUMO

Saturn's ionosphere is produced when the otherwise neutral atmosphere is exposed to a flow of energetic charged particles or solar radiation. At low latitudes the solar radiation should result in a weak planet-wide glow in the infrared, corresponding to the planet's uniform illumination by the Sun. The observed electron density of the low-latitude ionosphere, however, is lower and its temperature higher than predicted by models. A planet-to-ring magnetic connection has been previously suggested, in which an influx of water from the rings could explain the lower-than-expected electron densities in Saturn's atmosphere. Here we report the detection of a pattern of features, extending across a broad latitude band from 25 to 60 degrees, that is superposed on the lower-latitude background glow, with peaks in emission that map along the planet's magnetic field lines to gaps in Saturn's rings. This pattern implies the transfer of charged species derived from water from the ring-plane to the ionosphere, an influx on a global scale, flooding between 30 to 43 per cent of the surface of Saturn's upper atmosphere. This ring 'rain' is important in modulating ionospheric emissions and suppressing electron densities.

15.
Case Rep Pulmonol ; 2012: 595402, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23198240

RESUMO

We report a case of nephropleural fistula causing empyema and respiratory failure in a 68-year-old gentleman with a long history of urological problems including recurrent nephrolithiasis and urinary tract infections. He was admitted with sepsis, a productive cough, pyuria, and reduced breath sounds over the left hemithorax. Radiological imaging revealed a fistulous connection between a left-sided perinephric abscess and the pleural space. He was commenced on broad spectrum intravenous antibiotics but developed progressive respiratory failure requiring intensive care admission. Urinary and pleural aspirates cultured facultative anaerobic pathogens with identical resistance patterns. Drainage of thoracic and perinephric collections was carried out, allowing him to be extubated after 24 hours and discharged home after 18 days on an extended course of oral antibiotics. Left nephrectomy is now planned after a period of convalescence. Empyema developing in patients with known urolithiasis should alert the treating physician to the possibility that a pathological communication has formed especially if typical urinary tract pathogens are cultured from respiratory sampling.

16.
Animal ; 6(6): 920-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22558962

RESUMO

The objectives of the study were to determine the effect of the partial replacement of soyabean meal and rapeseed meal with feed grade urea or a slow-release urea on the performance, metabolism and whole-tract digestibility in mid-lactation dairy cows. Forty-two Holstein-Friesian dairy cows were allocated to one of three dietary treatments in each of three periods of 5 weeks duration in a Latin square design. Control (C) cows were offered a total mixed ration based on grass and maize silages and straight feeds that included 93 g/kg dry matter (DM) soyabean meal and 61 g/kg DM rapeseed meal. Cows that received either of the other two treatments were offered the same basal ration with the replacement of 28 g/kg DM soyabean and 19 g/kg DM rapeseed meal with either 5 g/kg DM feed grade urea (U) or 5.5 g/kg DM of the slow-release urea (S; Optigen®; Alltech Inc., Kentucky, USA), with the content of maize silage increasing. There was no effect (P > 0.05) of dietary treatment on DM intake, which averaged 22.5 kg/day. Similarly, there was no effect (P > 0.05) of treatment on daily milk or milk fat yield but there was a trend (P = 0.09) for cows offered either of the diets containing urea to have a higher milk fat content (average of 40.1 g/kg for U and S v. 38.9 g/kg for C). Milk true protein concentration and yield were not affected by treatment (P > 0.05). Milk yield from forage and N efficiency (g milk N output/g N intake) were highest (P < 0.01) in cows when offered S and lowest in C, with cows receiving U having intermediate values. Cows offered S also tended to have the highest live weight gain (0.38 kg/day) followed by U (0.23 kg/day) and C (0.01 kg/day; P = 0.07). Plasma urea concentrations were higher (P < 0.05) at 2 and 4 h post feeding in cows when offered U and lowest in C, with animals receiving S having intermediate values. There was no effect (P > 0.05) of treatment on whole-tract digestibility. In conclusion, the partial replacement of soyabean meal and rapeseed meal with feed grade urea or a slow-release urea can be achieved without affecting milk performance or diet digestibility, with the efficiency of conversion of dietary N into milk being improved when the slow-release urea was fed.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos , Bovinos/metabolismo , Digestão , Leite/metabolismo , Ureia/administração & dosagem , Animais , Brassica rapa/química , Dieta/veterinária , Feminino , Lactação , Valor Nutritivo , Distribuição Aleatória , Ovinos/metabolismo , Ovinos/fisiologia , Glycine max/química
17.
Science ; 330(6012): 1813-5, 2010 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-21109635

RESUMO

The flyby measurements of the Cassini spacecraft at Saturn's moon Rhea reveal a tenuous oxygen (O(2))-carbon dioxide (CO(2)) atmosphere. The atmosphere appears to be sustained by chemical decomposition of the surface water ice under irradiation from Saturn's magnetospheric plasma. This in situ detection of an oxidizing atmosphere is consistent with remote observations of other icy bodies, such as Jupiter's moons Europa and Ganymede, and suggestive of a reservoir of radiolytic O(2) locked within Rhea's ice. The presence of CO(2) suggests radiolysis reactions between surface oxidants and organics or sputtering and/or outgassing of CO(2) endogenic to Rhea's ice. Observations of outflowing positive and negative ions give evidence for pickup ionization as a major atmospheric loss mechanism.


Assuntos
Dióxido de Carbono , Oxigênio , Saturno , Atmosfera , Meio Ambiente Extraterreno , Gelo , Espectrometria de Massas , Processos Fotoquímicos , Astronave
18.
Cytogenet Genome Res ; 120(3-4): 302-12, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18504359

RESUMO

Meiosis is a fundamental and evolutionarily conserved process that is central to the life cycles of all sexually reproducing eukaryotes. An understanding of this process is critical to furthering research on reproduction, fertility, genetics and breeding. Plants have been used extensively in cytogenetic studies of meiosis during the last century. Until recently, our knowledge of the molecular and functional aspects of meiosis has emerged from the study of non-plant model organisms, especially budding yeast. However, the emergence of Arabidopsis thaliana as the model organism for plant molecular biology and genetics has enabled significant progress in the characterisation of key genes and proteins controlling plant meiosis. The development of molecular and cytological techniques in Arabidopsis, besides allowing investigation of the more conserved aspects of meiosis, are also providing insights into features of this complex process which may vary between organisms. This review highlights an example of this recent progress by focussing on ASY1, a meiosis-specific Arabidopsis protein which shares some similarity with the N-terminus region of the yeast axial core-associated protein, HOP1, a component of a multiprotein complex which acts as a meiosis-specific barrier to sister-chromatid repair in budding yeast. In the absence of ASY1, synapsis is interrupted and chiasma formation is dramatically reduced. ASY1 protein is initially detected during early meiotic G2 as numerous foci distributed over the chromatin. As G2 progresses the signal appears to be increasingly continuous and is closely associated with the axial elements. State-of-the-art cytogenetic techniques have revealed that initiation of recombination is synchronised with the formation of the chromosome axis. Furthermore, in the context of the developing chromosome axes, ASY1 plays a crucial role in co-ordinating the activity of a key member of the homologous recombination machinery, AtDMC1.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Meiose/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Cromossomos de Plantas/genética , Troca Genética , Citogenética , DNA de Plantas/genética , Proteínas de Ligação a DNA/fisiologia , Genes de Plantas , Meiose/fisiologia , Modelos Genéticos , Mutação , Recombinação Genética
19.
Science ; 319(5868): 1380-4, 2008 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-18323452

RESUMO

Saturn's moon Rhea had been considered massive enough to retain a thin, externally generated atmosphere capable of locally affecting Saturn's magnetosphere. The Cassini spacecraft's in situ observations reveal that energetic electrons are depleted in the moon's vicinity. The absence of a substantial exosphere implies that Rhea's magnetospheric interaction region, rather than being exclusively induced by sputtered gas and its products, likely contains solid material that can absorb magnetospheric particles. Combined observations from several instruments suggest that this material is in the form of grains and boulders up to several decimetres in size and orbits Rhea as an equatorial debris disk. Within this disk may reside denser, discrete rings or arcs of material.

20.
Biochem Soc Trans ; 34(Pt 4): 542-4, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16856855

RESUMO

Immunocytochemistry reveals that the Arabidopsis mismatch repair proteins AtMSH4, AtMLH3 and AtMLH1 are expressed during prophase I of meiosis. Expression of AtMSH4 precedes AtMLH3 and AtMLH1 which co-localize as foci during pachytene. Co-localization between AtMSH4 and AtMLH3 occurs, but appears transient. AtMLH3 foci are not detected in an Atmsh4 mutant. However, localization of AtMSH4 is unaffected in Atmlh3, suggesting that recombination may proceed to dHj (double Holliday junction) formation. Mean chiasma frequency in Atmsh4 is reduced to 1.55 compared with 9.86 in wild-type. In contrast with wild-type, the distribution of residual crossovers in Atmsh4 closely fits a Poisson distribution. This is consistent with a two-pathway model for meiotic crossing-over whereby most crossovers occur via an AtMSH4-dependent pathway that is subject to interference, with the remaining crossovers arising via an interference-independent pathway. Loss of AtMLH3 results in an approx. 60% reduction in crossovers. Results suggest that dHj resolution can occur, but in contrast with wild-type where most or all dHjs are directed to form crossovers, the outcome is biased in favour of a non-crossover outcome. The results are compatible with a model whereby the MutL complex maintains or imposes a dHj conformation that ensures crossover formation.


Assuntos
Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Transporte/genética , Enzimas Reparadoras do DNA/genética , Proteínas Nucleares/genética , Recombinação Genética/genética , Humanos , Meiose
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...