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1.
Artigo em Inglês | MEDLINE | ID: mdl-38858799

RESUMO

OBJECTIVE: Extracellular volume fraction (fECV) and liver and spleen size have been correlated with liver fibrosis stages and cirrhosis. The purpose of the current study was to determine the predictive value of fECV alone and in conjunction with measurement of liver and spleen size for severity of liver fibrosis. METHODS: This was a retrospective study of 95 subjects (65 with liver biopsy and 30 controls). Spearman rank correlation coefficient was used to assess correlation between radiological markers and fibrosis stage. Receiver operating characteristic analysis was performed to assess the discriminative ability of radiological markers for significant (F2+) and advanced (F3+) fibrosis and cirrhosis (F4), by reporting the area under the curve (AUC). RESULTS: The cohort had a mean age of 51.4 ± 14.4 years, and 52 were female (55%). There were 36, 5, 6, 9, and 39 in fibrosis stages F0, F1, F2, F3, and F4, respectively. Spleen volume alone showed the highest correlation (r = 0.552, P < 0.001) and AUCs of 0.823, 0.807, and 0.785 for identification of significant and advanced fibrosis and cirrhosis, respectively. Adding fECV to spleen length improved AUCs (0.764, 0.745, and 0.717 to 0.812, 0.781, and 0.738, respectively) compared with splenic length alone. However, adding fECV to spleen volume did not improve the AUCs for significant or advanced fibrosis or cirrhosis. CONCLUSIONS: Spleen size (measured in length or volume) showed better correlation with liver fibrosis stages compared with fECV. The combination of fECV and spleen length had higher accuracy compared with fECV alone or spleen length alone.

2.
Radiology ; 307(5): e222855, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37367445

RESUMO

Background Various limitations have impacted research evaluating reader agreement for Liver Imaging Reporting and Data System (LI-RADS). Purpose To assess reader agreement of LI-RADS in an international multicenter multireader setting using scrollable images. Materials and Methods This retrospective study used deidentified clinical multiphase CT and MRI and reports with at least one untreated observation from six institutions and three countries; only qualifying examinations were submitted. Examination dates were October 2017 to August 2018 at the coordinating center. One untreated observation per examination was randomly selected using observation identifiers, and its clinically assigned features were extracted from the report. The corresponding LI-RADS version 2018 category was computed as a rescored clinical read. Each examination was randomly assigned to two of 43 research readers who independently scored the observation. Agreement for an ordinal modified four-category LI-RADS scale (LR-1, definitely benign; LR-2, probably benign; LR-3, intermediate probability of malignancy; LR-4, probably hepatocellular carcinoma [HCC]; LR-5, definitely HCC; LR-M, probably malignant but not HCC specific; and LR-TIV, tumor in vein) was computed using intraclass correlation coefficients (ICCs). Agreement was also computed for dichotomized malignancy (LR-4, LR-5, LR-M, and LR-TIV), LR-5, and LR-M. Agreement was compared between research-versus-research reads and research-versus-clinical reads. Results The study population consisted of 484 patients (mean age, 62 years ± 10 [SD]; 156 women; 93 CT examinations, 391 MRI examinations). ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68 (95% CI: 0.61, 0.73), 0.63 (95% CI: 0.55, 0.70), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95% CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68 vs 0.62, respectively; P = .03) and for dichotomized malignancy (ICC, 0.63 vs 0.53, respectively; P = .005), but not for LR-5 (P = .14) or LR-M (P = .94). Conclusion There was moderate agreement for LI-RADS version 2018 overall. For some comparisons, research-versus-research reader agreement was higher than research-versus-clinical reader agreement, indicating differences between the clinical and research environments that warrant further study. © RSNA, 2023 Supplemental material is available for this article. See also the editorials by Johnson and Galgano and Smith in this issue.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Feminino , Pessoa de Meia-Idade , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X , Meios de Contraste , Sensibilidade e Especificidade
3.
J Vasc Interv Radiol ; 33(6): 660-667, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35278638

RESUMO

PURPOSE: To investigate the safety and efficacy of an aqueous polyethylene glycol-based liquid embolic agent, Embrace Hydrogel Embolic System (HES), in the treatment of benign and malignant hypervascular tumors. MATERIALS AND METHODS: A prospective, single-arm, multicenter study included 8 patients, 5 males and 3 females, with a median age of 58.5 years (30-85 years), who underwent embolization in 8 tumors between October 2019 and May 2020. Technical success was defined as successful delivery of HES to the index vessel, with disappearance of >90% of the targeted vascular enhancement or, for portal vein embolization, occlusion of the portal branches to the liver segments for future resection. The volume of HES administered, ease of use (5 point Likert scale), administration time, and adverse events (AEs) were recorded. Evaluation was performed at 7, 30, and 90 days via clinical assessment and blood testing, and follow-up imaging was performed at 30 days. RESULTS: Eight patients were enrolled, and 10 embolizations were performed in 8 lesions. Tumors included hepatocellular carcinoma (n = 4), renal angiomyolipoma (n = 3), and intrahepatic cholangiocarcinoma (n = 1). Technical success was 100%, and the average ease of use was 3.3 ± 1.0 SD. The HES delivery time was 1-28 minutes (median, 16.5 minutes), and the HES volume injected was 0.4-4.0 mL (median, 1.3 mL). All patients reached 30-day follow-up with imaging, and 6 patients reached 90-day follow-up. There were 3 serious AEs in 2 patients that were unrelated to the embolic agent. CONCLUSION: HES resulted in a 100% embolization technical success rate. The product ease of use was acceptable, and no target vessel recanalization was noted on follow-up imaging at 30 days.


Assuntos
Angiomiolipoma , Neoplasias dos Ductos Biliares , Embolização Terapêutica , Neoplasias Renais , Neoplasias Hepáticas , Angiomiolipoma/terapia , Neoplasias dos Ductos Biliares/terapia , Ductos Biliares Intra-Hepáticos , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/métodos , Feminino , Humanos , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/etiologia , Neoplasias Renais/terapia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/efeitos adversos , Estudos Prospectivos , Resultado do Tratamento
4.
J Anat ; 239(1): 184-206, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33660262

RESUMO

The radiation of archosauromorph reptiles in the Triassic Period produced an unprecedented collection of diverse and disparate forms with a mix of varied ecologies and body sizes. Some of these forms were completely unique to the Triassic, whereas others were converged on by later members of Archosauromorpha. One of the most striking examples of this is with Triopticus primus, the early dome-headed form later mimicked by pachycephalosaurid dinosaurs. Here we fully describe the cranial anatomy of Triopticus primus, but also recognize a second dome-headed form from a Upper Triassic deposit in present-day India. The new taxon, Kranosaura kuttyi gen. et sp. nov., is likely the sister taxon of Triopticus primus based on the presence of a greatly expanded skull roof with a deep dorsal opening (possibly the pineal opening) through the dome, similar cranial sculpturing, and a skull table that is expanded more posterior than the posterior extent of the basioccipital. However, the dome of Kranosaura kuttyi gen. et sp. nov. extends anterodorsally, unlike that of any other archosauromorph. Histological sections and computed tomographic reconstructions through the skull of Kranosaura kuttyi gen. et sp. nov. further reveal the uniqueness of the dome of these early archosauromorphs. Moreover, our integrated analysis further demonstrates that there are many ways to create a dome in Amniota. The presence of 'dome-headed' archosauromorphs at two localities on the western and eastern portions of Pangea suggests that these archosauromorphs were widespread and are likely part of more assemblages than currently recognized.


Assuntos
Distribuição Animal , Dinossauros/anatomia & histologia , Fósseis/anatomia & histologia , Crânio/anatomia & histologia , Animais
5.
Med J Aust ; 214(10): 475-483, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33314233

RESUMO

INTRODUCTION: Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths both globally and in Australia. Surveillance for HCC in at-risk populations allows diagnosis at an early stage, when potentially curable. However, most Australians diagnosed with HCC die of the cancer or of liver disease. In the changing landscape of HCC management, unique challenges may lead to clinical practice variation. As a result, there is a need to identify best practice management of HCC in an Australian context. This consensus statement has been developed for health professionals involved in the care of adult patients with HCC in Australia. It is applicable to specialists, general medical practitioners, nurses, health coordinators and hospital administrators. METHODS AND RECOMMENDATIONS: This statement has been developed by specialists in hepatology, radiology, surgery, oncology, palliative care, and primary care, including medical practitioners and nurses. The statement addresses four main areas relevant to HCC management: epidemiology and incidence, diagnosis, treatment, and patient management. A modified Delphi process was used to reach consensus on 31 recommendations. Principal recommendations include the adoption of surveillance strategies, use of multidisciplinary meetings, diagnosis, treatment options and patient management. CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT: This consensus statement will simplify HCC patient management and reduce clinical variation. Ultimately, this should result in better outcomes for patients with HCC.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Adulto , Austrália/epidemiologia , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etnologia , Comorbidade , Diagnóstico por Imagem , Humanos , Incidência , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etnologia , Havaiano Nativo ou Outro Ilhéu do Pacífico/estatística & dados numéricos , Estadiamento de Neoplasias , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Equipe de Assistência ao Paciente , Vigilância da População
6.
Circulation ; 139(3): 337-346, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30586728

RESUMO

BACKGROUND: In ST-segment-elevation myocardial infarction (STEMI), infarct size correlates directly with heart failure and mortality. Preclinical testing has shown that, in comparison with reperfusion alone, mechanically unloading the left ventricle (LV) before reperfusion reduces infarct size and that 30 minutes of unloading activates a cardioprotective program that limits reperfusion injury. The DTU-STEMI pilot trial (Door-To-Unload in STEMI Pilot Trial) represents the first exploratory study testing whether LV unloading and delayed reperfusion in patients with STEMI without cardiogenic shock is safe and feasible. METHODS: In a multicenter, prospective, randomized exploratory safety and feasibility trial, we assigned 50 patients with anterior STEMI to LV unloading by using the Impella CP followed by immediate reperfusion (U-IR) versus delayed reperfusion after 30 minutes of unloading (U-DR). The primary safety outcome was a composite of major adverse cardiovascular and cerebrovascular events at 30 days. Efficacy parameters included the assessment of infarct size by using cardiac magnetic resonance imaging. RESULTS: All patients completed the U-IR (n=25) or U-DR (n=25) protocols with respective mean door-to-balloon times of 72 versus 97 minutes. Major adverse cardiovascular and cerebrovascular event rates were not statistically different between the U-IR versus U-DR groups (8% versus 12%, respectively, P=0.99). In comparison with the U-IR group, delaying reperfusion in the U-DR group did not affect 30-day mean infarct size measured as a percentage of LV mass (15±12% versus 13±11%, U-IR versus U-DR, P=0.53). CONCLUSIONS: We report that LV unloading using the Impella CP device with a 30-minute delay before reperfusion is feasible within a relatively short time period in anterior STEMI. The DTU-STEMI pilot trial did not identify prohibitive safety signals that would preclude proceeding to a larger pivotal study of LV unloading before reperfusion. An appropriately powered pivotal trial comparing LV unloading before reperfusion to the current standard of care is required. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03000270.


Assuntos
Infarto Miocárdico de Parede Anterior/terapia , Coração Auxiliar , Reperfusão Miocárdica/métodos , Implantação de Prótese/instrumentação , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Função Ventricular Esquerda , Adulto , Idoso , Idoso de 80 Anos ou mais , Infarto Miocárdico de Parede Anterior/diagnóstico por imagem , Infarto Miocárdico de Parede Anterior/fisiopatologia , Transtornos Cerebrovasculares/etiologia , Transtornos Cerebrovasculares/fisiopatologia , Transtornos Cerebrovasculares/prevenção & controle , Estudos de Viabilidade , Feminino , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reperfusão Miocárdica/efeitos adversos , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Projetos Piloto , Estudos Prospectivos , Implantação de Prótese/efeitos adversos , Recuperação de Função Fisiológica , Recidiva , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Adulto Jovem
7.
BMC Cancer ; 20(1): 483, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32471447

RESUMO

BACKGROUND: Repeat transarterial chemoembolisation (rTACE) is often required for hepatocellular carcinoma (HCC) to achieve disease control, however, current practice guidelines regarding treatment allocation vary significantly. This study aims to identify key factors associated with patient survival following rTACE to facilitate treatment allocation and prognostic discussion. METHOD: Patients with HCC undergoing rTACE at six Australian tertiary centers from 2009 to 2014 were included. Variables encompassing clinical, tumour, treatment type and response factors were analysed against the primary outcome of overall survival. Univariate analysis and multivariate Cox regression modelling were used to identify factors pre- and post-TACE therapy significantly associated with survival. RESULTS: Total of 292 consecutive patients underwent rTACE with mainly Child Pugh A cirrhosis (61%) and BCLC stage A (57%) disease. Median overall survival (OS) was 30 months (IQR 15.2-50.2) from initial TACE. On multivariate analysis greater tumour number (p = 0.02), higher serum bilirubin (p = 0.007) post initial TACE, and hepatic decompensation (p = 0.001) post second TACE were associated with reduced survival. Patients with serum AFP ≥ 200 ng/ml following initial TACE had lower survival (p = 0.001), compared to patients with serum AFP level that remained < 200 ng/ml post-initial TACE, with an overall survival of 19.4 months versus 34.7 months (p = 0.0001) respectively. CONCLUSION: Serum AFP level following initial treatment in patients undergoing repeat TACE for HCC is a simple and useful clinical prognostic marker. Moreover, it has the potential to facilitate appropriate patient selection for rTACE particularly when used in conjunction with baseline tumour burden and severity of hepatic dysfunction post-initial TACE.


Assuntos
Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Recidiva Local de Neoplasia/terapia , alfa-Fetoproteínas/análise , Idoso , Austrália/epidemiologia , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/mortalidade , Quimioembolização Terapêutica/efeitos adversos , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/mortalidade , Seleção de Pacientes , Prognóstico , Retratamento/efeitos adversos , Retratamento/métodos , Estudos Retrospectivos , Resultado do Tratamento
8.
Ann Bot ; 123(5): 747-766, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-30715125

RESUMO

BACKGROUND: Enset (Ensete ventricosum, Musaceae) is an African crop that currently provides the staple food for approx. 20 million Ethiopians. Whilst wild enset grows over much of East and Southern Africa and the genus extends across Asia to China, it has only ever been domesticated in the Ethiopian Highlands. Here, smallholder farmers cultivate hundreds of landraces across diverse climatic and agroecological systems. SCOPE: Enset has several important food security traits. It grows over a relatively wide range of conditions, is somewhat drought-tolerant, and can be harvested at any time of the year, over several years. It provides an important dietary starch source, as well as fibres, medicines, animal fodder, roofing and packaging. It stabilizes soils and microclimates and has significant cultural importance. In contrast to the other cultivated species in the family Musaceae (banana), enset has received relatively little research attention. Here, we review and critically evaluate existing research, outline available genomic and germplasm resources, aspects of pathology, and explore avenues for crop development. CONCLUSION: Enset is an underexploited starch crop with significant potential in Ethiopia and beyond. Research is lacking in several key areas: empirical studies on the efficacy of current agronomic practices, the genetic diversity of landraces, approaches to systematic breeding, characterization of existing and emerging diseases, adaptability to new ranges and land-use change, the projected impact of climate change, conservation of crop wild relatives, by-products or co-products or non-starch uses, and the enset microbiome. We also highlight the limited availability of enset germplasm in living collections and seedbanks, and the lack of knowledge of reproductive and germination biology needed to underpin future breeding. By reviewing the current state of the art in enset research and identifying gaps and opportunities, we hope to catalyse the development and sustainable exploitation of this neglected starch crop.


Assuntos
Musaceae , Amido , Ásia , China , Etiópia
12.
Proc Natl Acad Sci U S A ; 111(28): 10245-50, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24982159

RESUMO

The placement of over 50 skulls of the well-known horned dinosaur Triceratops within a stratigraphic framework for the Upper Cretaceous Hell Creek Formation (HCF) of Montana reveals the evolutionary transformation of this genus. Specimens referable to the two recognized morphospecies of Triceratops, T. horridus and T. prorsus, are stratigraphically separated within the HCF with the T. prorsus morphology recovered in the upper third of the formation and T. horridus found lower in the formation. Hypotheses that these morphospecies represent sexual or ontogenetic variation within a single species are thus untenable. Stratigraphic placement of specimens appears to reveal ancestor-descendant relationships. Transitional morphologies are found in the middle unit of the formation, a finding that is consistent with the evolution of Triceratops being characterized by anagenesis, the transformation of a lineage over time. Variation among specimens from this critical stratigraphic zone may indicate a branching event in the Triceratops lineage. Purely cladogenetic interpretations of the HCF dataset imply greater diversity within the formation. These findings underscore the critical role of stratigraphic data in deciphering evolutionary patterns in the Dinosauria.


Assuntos
Evolução Biológica , Dinossauros/fisiologia , Fósseis , Animais , Dinossauros/classificação , Montana
14.
Proc Natl Acad Sci U S A ; 109(18): 7061-6, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22509009

RESUMO

Following general anesthesia, people are often confused about the time of day and experience sleep disruption and fatigue. It has been hypothesized that these symptoms may be caused by general anesthesia affecting the circadian clock. The circadian clock is fundamental to our well-being because it regulates almost all aspects of our daily biochemistry, physiology, and behavior. Here, we investigated the effects of the most common general anesthetic, isoflurane, on time perception and the circadian clock using the honeybee (Apis mellifera) as a model. A 6-h daytime anesthetic systematically altered the time-compensated sun compass orientation of the bees, with a mean anticlockwise shift in vanishing bearing of 87° in the Southern Hemisphere and a clockwise shift in flight direction of 58° in the Northern Hemisphere. Using the same 6-h anesthetic treatment, time-trained bees showed a delay in the start of foraging of 3.3 h, and whole-hive locomotor-activity rhythms were delayed by an average of 4.3 h. We show that these effects are all attributable to a phase delay in the core molecular clockwork. mRNA oscillations of the central clock genes cryptochrome-m and period were delayed by 4.9 and 4.3 h, respectively. However, this effect is dependent on the time of day of administration, as is common for clock effects, and nighttime anesthesia did not shift the clock. Taken together, our results suggest that general anesthesia during the day causes a persistent and marked shift of the clock effectively inducing "jet lag" and causing impaired time perception. Managing this effect in humans is likely to help expedite postoperative recovery.


Assuntos
Anestesia Geral/efeitos adversos , Abelhas/fisiologia , Relógios Circadianos/fisiologia , Percepção do Tempo/fisiologia , Ciclos de Atividade/efeitos dos fármacos , Ciclos de Atividade/fisiologia , Anestésicos Gerais/efeitos adversos , Animais , Sequência de Bases , Abelhas/efeitos dos fármacos , Abelhas/genética , Relógios Circadianos/efeitos dos fármacos , Relógios Circadianos/genética , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Voo Animal/efeitos dos fármacos , Voo Animal/fisiologia , Genes de Insetos , Humanos , Isoflurano/efeitos adversos , Modelos Animais , Fotoperíodo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Percepção do Tempo/efeitos dos fármacos
15.
Ren Fail ; 37(1): 175-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25365636

RESUMO

BACKGROUND: Terlipressin improves renal function in some patients with type-1 hepato-renal syndrome (HRS). Renal contrast-enhanced ultrasound (CEUS), a novel imaging modality, may help to predict terlipressin responsiveness. OBJECTIVES: We used CEUS to estimate the effect of terlipressin on the renal cortical microcirculation in type-1 HRS. METHODS: We performed renal CEUS scans with destruction-replenishment sequences using Sonovue(®) (Bracco, Milano Italy) as a contrast agent at baseline and after the intravenous administration of 1 mg of terlipressin, in four patients with type-1 HRS. We analyzed video sequences offline using dedicated software. We derived a perfusion index (PI) at each time point for each patient. RESULTS: Patients 1 and 2 had severe presentation and were admitted to the intensive care unit. Both showed a marked increase in PI (+216% and + 567% of baseline) in response to terlipressin. Patients 3 and 4 had less severe presentations and had a decrease in PI (-53% and -20% of baseline) in response to terlipressin. Patients 1, 2, and 4, but not patient 3, responded to terlipressin therapy with a decrease in serum creatinine to <150 µmol/L. CONCLUSIONS: CEUS detected changes in renal cortical microcirculation in response to terlipressin and demonstrated heterogeneous microvascular responses to terlipressin. These initial proof-of-concept findings justify future investigations.


Assuntos
Síndrome Hepatorrenal , Córtex Renal , Lipressina/análogos & derivados , Microcirculação/efeitos dos fármacos , Imagem de Perfusão/métodos , Administração Intravenosa , Anti-Hipertensivos/administração & dosagem , Síndrome Hepatorrenal/diagnóstico , Síndrome Hepatorrenal/tratamento farmacológico , Humanos , Aumento da Imagem/métodos , Córtex Renal/irrigação sanguínea , Córtex Renal/diagnóstico por imagem , Lipressina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Terlipressina , Resultado do Tratamento , Ultrassonografia
16.
Proc Biol Sci ; 281(1775): 20132741, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24285202

RESUMO

The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-αFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25°C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O2 > HB - O2 > -O2 >> +O2. The well-known O2/haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O2/haeme interactions in the preservation of fossil soft tissues.


Assuntos
Fósseis , Ferro/química , Oxigênio/química , Animais , Dinossauros/anatomia & histologia , Ferro/análise , Microscopia Eletrônica de Transmissão , Struthioniformes/sangue
17.
Crit Care ; 18(6): 653, 2014 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-25439317

RESUMO

INTRODUCTION: We used contrast-enhanced ultrasound (CEUS) to estimate the effect of an increase in mean arterial pressure (MAP) induced by noradrenaline infusion on renal microvascular cortical perfusion in critically ill patients. METHODS: Twelve patients requiring a noradrenaline infusion to maintain a MAP more than 60 mmHg within 48 hours of intensive care unit admission were included in the study. Renal CEUS scans with destruction-replenishment sequences and Sonovue® (Bracco, Milano Italy) as a contrast agent, were performed at baseline (MAP 60 to 65 mmHg) and after a noradrenaline-induced increase in MAP to 80 to 85 mmHg. RESULTS: There was no adverse effect associated with ultrasound contrast agent administration or increase in noradrenaline infusion rate. Adequate images were obtained in all patients at all study times. To reach the higher MAP target, median noradrenaline infusion rate was increased from 10 to 14 µg/min. Noradrenaline-induced increases in MAP were not associated with a significant change in overall CEUS derived mean perfusion indices (median perfusion index 3056 (interquartile range: 2438 to 6771) arbitrary units (a.u.) at baseline versus 4101 (3067 to 5981) a.u. after MAP increase, P = 0.38). At individual level, however, we observed important heterogeneity in responses (range -51% to +97% changes from baseline). CONCLUSIONS: A noradrenaline-induced increase in MAP was not associated with an overall increase in renal cortical perfusion as estimated by CEUS. However, at individual level, such response was heterogeneous and unpredictable suggesting great variability in pressure responsiveness within a cohort with a similar clinical phenotype.


Assuntos
Meios de Contraste , Córtex Renal/irrigação sanguínea , Córtex Renal/diagnóstico por imagem , Microcirculação/fisiologia , Norepinefrina/administração & dosagem , Circulação Renal/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Infusões Intravenosas , Córtex Renal/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Circulação Renal/efeitos dos fármacos , Ultrassonografia
18.
Insights Imaging ; 15(1): 146, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38886297

RESUMO

Chronic liver disease is responsible for significant morbidity and mortality worldwide. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) can fully visualise the liver and adjacent structures in the upper abdomen providing a reproducible assessment of the liver and biliary system and can detect features of portal hypertension. Subjective interpretation of CT and MRI in the assessment of liver parenchyma for early and advanced stages of fibrosis (pre-cirrhosis), as well as severity of portal hypertension, is limited. Quantitative and reproducible measurements of hepatic and splenic volumes have been shown to correlate with fibrosis staging, clinical outcomes, and mortality. In this review, we will explore the role of volumetric measurements in relation to diagnosis, assessment of severity and prediction of outcomes in chronic liver disease patients. We conclude that volumetric analysis of the liver and spleen can provide important information in such patients, has the potential to stratify patients' stage of hepatic fibrosis and disease severity, and can provide critical prognostic information. CRITICAL RELEVANCE STATEMENT: This review highlights the role of volumetric measurements of the liver and spleen using CT and MRI in relation to diagnosis, assessment of severity, and prediction of outcomes in chronic liver disease patients. KEY POINTS: Volumetry of the liver and spleen using CT and MRI correlates with hepatic fibrosis stages and cirrhosis. Volumetric measurements correlate with chronic liver disease outcomes. Fully automated methods for volumetry are required for implementation into routine clinical practice.

19.
BMJ Case Rep ; 17(2)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38320958

RESUMO

A man in his 60s with a virgin abdomen presented with sudden-onset generalised abdominal pain and fevers. The night prior, he snacked on supermarket purchased dehydrated apples. CT abdomen and pelvis revealed small bowel obstruction (SBO) to the mid ileum and small amount of free fluid within the pelvis. The patient underwent emergency exploratory laparotomy. High-grade SBO was identified, caused by large obstructing phytobezoars, with three further proximal large phytobezoars identified. All four phytobezoars were extracted and found to be rehydrated pieces of dehydrated apple that had increased in size in the gastrointestinal tract. The patient was later found to have further phytobezoars in the stomach which passed conservatively. The patient recovered well. This case demonstrates the challenges of preoperative radiological diagnosis in phytobezoar-related SBO and the significance of enterotomy orientation and closure to ensure a safe repair to withstand the passage of any residual rehydrating phytobezoars.


Assuntos
Bezoares , Obstrução Intestinal , Malus , Masculino , Humanos , Intestino Delgado/cirurgia , Obstrução Intestinal/etiologia , Bezoares/cirurgia , Ingestão de Alimentos
20.
Crit Care ; 17(4): R138, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23849270

RESUMO

INTRODUCTION: Contrast-enhanced ultrasound (CEUS) is a new technique that might enable portable and non-invasive organ perfusion quantification at the bedside. However, it has not yet been tested in critically ill patients. We sought to establish CEUS's feasibility, safety, reproducibility and potential diagnostic value in the assessment of renal cortical perfusion in the peri-operative period in cardiac surgery patients. METHODS: We recruited twelve patients deemed at risk of acute kidney injury (AKI) planned for elective cardiac surgery. We performed renal CEUS with destruction-replenishment sequences before the operation, on ICU arrival and the day following the admission. Enhancement was obtained with Sonovue® (Bracco, Milano, Italy) at an infusion rate of 1 ml/min. We collected hemodynamic parameters before, during and after contrast agent infusion. At each study time, we obtained five video sequences, which were analysed using dedicated software by two independent radiologists blinded to patient and time. The main output was a perfusion index (PI), corresponding to the ratio of relative blood volume (RBV) over mean transit time (mTT). RESULTS: All 36 renal CEUS studies, including 24 in the immediate post-operative period could be performed and were well tolerated. Correlation between readers for PI was excellent (R2 = 0.96, P < 0.0001). Compared with baseline, there was no overall difference in median PI's on ICU admission. However, the day after surgery, median PI's had decreased by 50% (P < 0.01) (22% decrease in RBV (P = 0.09); 48% increase in mTT (P = 0.04), both suggestive of decreased perfusion). These differences persisted after correction for haemoglobin; vasopressors use and mean arterial pressure. Four patients developed AKI in the post-operative period. CONCLUSIONS: CEUS appears feasible and well-tolerated in patients undergoing cardiac surgery even immediately after ICU admission. CEUS derived-parameters suggest a decrease in renal perfusion occurring within 24 hours of surgery.


Assuntos
Injúria Renal Aguda/diagnóstico por imagem , Procedimentos Cirúrgicos Cardíacos , Meios de Contraste , Córtex Renal/irrigação sanguínea , Córtex Renal/diagnóstico por imagem , Microcirculação , Complicações Pós-Operatórias/diagnóstico por imagem , Idoso , Volume Sanguíneo , Cuidados Críticos , Humanos , Variações Dependentes do Observador , Período Perioperatório , Projetos Piloto , Circulação Renal , Ultrassonografia
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